The Palimpsest Hound

A reconstructed Tindalosian manifestation for Cthulhu Eternal

The first photograph showed four depressions in wet plaster, too deep for fingertips and too evenly spaced to be tools.

The second showed the same marks six feet higher, up where the wall met the ceiling.

The pathologist laid both photographs beside the victim’s wounds. He did not notice the room getting colder. He drew four lines between the punctures and added an arc to show how far the jaw had probably spread.

Something above him grew a mouth.

What was erased

A Palimpsest Hound is the same Hound of Tindalos whose earlier appearance was successfully erased, written back into the world a second time over the top of that erasure.

The first time around, someone did the work. Maybe the witness went through the Unremembering. The journal burned, the room came down, the photographs corrupted, and every surviving participant was talked into believing nothing unnatural had happened. For a while it holds. No reachable system carries a complete enough record of the encounter, the forced localization collapses, and the wounded thing slips back into angular time.

What the erasure never touches is the consequences. A widow keeps getting payments from an account her husband never mentioned. A hospital archive holds radiographs of injuries no known animal could leave. Three adjacent buildings hide rounded rooms under later renovations. A retired detective goes white at the smell of ozone. An otherwise flawless evidence-numbering sequence skips one folder. None of those facts is the encounter. Put enough of them on one table, though, and they might be enough to rebuild it.

The moment someone recognizes those leftovers as consequences of a single cause, the erased event becomes inferable again. Ordinary matter can once more tell the encounter-history apart from the one where nothing happened, and that forces the Hound back into finite form. It comes back as a palimpsest, a new body written over an erasure, assembled out of whatever the investigators managed to prove.

The unforgiving science of missing information

Here is a thing coding theory knows that intuition does not: an erasure is often easier to fix than a forgery, because the erasure tells you where to look. Change one transmitted symbol into another plausible symbol and the receiver has two problems, working out which symbol is wrong and then what should have been there instead. Delete the symbol outright and you have handed them the location for free; with enough surrounding redundancy, the structure around the gap can reconstruct its value. A message with an obvious hole in it can be easier to recover than one that has been quietly falsified.

The same thing is true of an erased encounter. A blank week in a diary, a missing evidence number, a corner that was rebuilt, a scar with no remembered injury behind it: each one marks the position of the loss. The erasure is a signpost pointing at exactly where the investigators should dig.

Let be the hypothesis that a Hound manifested, and let be the surviving consequences. Bayes updates how much you should believe it:

One inexplicable puncture wound proves nothing. Matching wounds, plus impossible tracks, plus blue residue, plus altered architecture, plus synchronized holes in people’s memories, are each ambiguous alone and crushing together. As the odds of all that evidence under boring explanations collapse, the posterior on the common cause climbs. That much is ordinary mathematics. The next sentence is where Tindalos comes in: here, a good enough reconstruction becomes a physical record in its own right. Once the surviving evidence backs one definite model strongly enough, that model renews the cross-temporal correlation from The Scent and hands the Hound the boundary conditions for its return. While the investigator is still deciding what kind of mouth made the wounds, her conclusion is already specifying the mouth that will arrive.

It appears consequence-first

An ordinary animal has anatomy first and leaves evidence second. A Palimpsest Hound is lived in the opposite order. Its footprints exist before its feet. Its wounds exist before its teeth. Its blue ichor gets chemically characterized before it grows tissue capable of bleeding. A witness remembers being watched before the creature has eyes. Every consequence the investigators solve narrows the range of bodies that could have produced it, and the projected Hound grows the matching organ to fit.

Describe it as an incomplete body, not a transparent one. Ghostly translucence tells the players the whole creature is there behind poor visibility, which is the wrong idea entirely. This thing looks revised. One edge is a bruise-coloured contour with no volume behind it. Its hide might carry the grain of a photograph, the ruled lines of a notebook, the crack pattern of old plaster, the livid branching of a scar. Under the newest surface the earlier drafts are still legible: crossed-out joints, silhouettes that do not agree, teeth set where the investigators first believed the wounds required them. The parts nobody has reconstructed yet look like deleted text, dents in your vision that dust and light and attention all bend around. You can tell something has been omitted without ever seeing the shape that belongs in the hole.

And a wrong but convincing conclusion does not stop it manifesting. It just gives the Hound the wrong organ. That anatomy works, because the record insists it must, but it fits badly, and the creature wearing it is in more pain, less stable, and usually more violent for it.

The Reconstruction Track

Use this instead of the ordinary Scent Track for this manifestation. It measures how completely the surviving consequences have been assembled into a single recoverable model.

Rating	State	Manifestation
0: Erasure	No accessible record points to a common unnatural cause.	Nothing. The prior encounter is functionally unrecoverable.
1: Lacuna	Someone notices a meaningful absence or an unexplained consequence.	Ozone, geometric unease, disturbed dust, repeated errors in dates or measurements.
2: Correspondence	Two or more consequences are shown to share a cause.	Tracks without feet, shadows without bodies, sounds from empty corners. It can watch but not yet attack.
3: Hypothesis	A Tindalosian explanation is credible and at least one working trait is reconstructed.	An unstable partial body forms at favourable angles, with only its reconstructed abilities.
4: Account	Investigators can tell a coherent story explaining most of the major evidence.	A complete Hound manifests and acts on its own.
5: Corroboration	Independent witnesses, analyses, or archives back the account.	Destroyed anatomy comes back fast. It can move between sites holding major records.
6: Redundancy	The reconstruction has been copied or baked into self-correcting records.	Killing any single witness, body, or archive means nothing. Only dismantling the distributed explanation frees it.

When to raise the track

Do not raise Reconstruction just because a Protagonist passed a skill test. That turns competence into a trap and makes investigation a farce. A successful test reveals evidence and possible connections. You raise the track only when a Protagonist, an NPC, or an analytical system does something that makes the common-cause model more recoverable: compares the files, writes the synthesis, confirms a prediction, briefs someone else, trains a model on the evidence, or otherwise commits the inference to a stable physical system. In practice, just ask the table: are you treating that as your working explanation? If they say yes and then preserve it or act on it, the reconstruction is real.

Raise the rating by 1 when the group:

• Shows that two previously separate consequences share an origin.
• Correctly predicts new evidence from the Hound hypothesis.
• Pins down the function responsible for a surviving trace.
• Produces a coherent timeline of the erased encounter.
• Gets genuinely independent corroboration.
• Copies or publishes a usable reconstruction.

A single act only earns more than one step if it remakes the whole investigation, like restoring a video that shows the original manifestation outright.

When to lower the track

Destroying a clue does not automatically lower Reconstruction. Once the conclusion has been learned and written down somewhere else, the original evidence is disposable. Lower the rating when the Protagonists:

• Remove the only recoverable link between major evidence clusters.
• Get two incompatible explanations equally well-supported.
• Destroy a unique functional inference before it is communicated or copied.
• Run the Unremembering on the one person capable of assembling the account.
• Split records so no person or system can compare them.
• Prove that a supposedly decisive relationship was false.

The rating cannot drop below the number of independently recoverable, coherent accounts still in existence. At Rating 5 or 6, lowering it is an operation against a network, not a bonfire.

Evidence becomes anatomy

Whenever Reconstruction hits 3, pick at least one trait the investigation has already established. The Hound gains that anatomy and its ability. Add more as the evidence gets interpreted.

Reconstructed evidence	Anatomy supplied	Mechanical consequence
Bite pattern or crushed bone	Jaw, teeth, anchoring muscle	Gains Finite Bite.
Tracks, displaced dust, or impossible approach	Limbs and locomotive joints	Gains full Movement and Discontinuous Pursuit.
Blue residue or contaminated tissue	Circulatory surface, projected flesh	Gains Armour and Recurrence.
Eyewitness terror, a sketched face, gaze-tracking data	Sensory pits or eyes	Gains Alertness, Tracking, and Seen Through the Record.
Rounded architecture or plastered corners	Angle-seeking organs	Gains Corner Emergence.
Contradictory timestamps or out-of-order events	A completed temporal axis	Gains Causal Backfill.
Autopsy tying deaths to one method	The required killing structure	Raises Finite Bite to full damage.
Destroyed journals, scrubbed disks, attacked archivists	Recognition of record-bearing systems	Gains Archive Sense; targets records intelligently.
Evidence of a successful Unremembering	Machinery for manipulating recall	Gains Excise the Witness.

The table is not exhaustive. Prove it flew and it grows whatever the evidence needs for flight. Prove it passed through a locked door and its projected body picks up a discontinuity that allows the same trick. Reward specific inference with specific horror.

Cthulhu Eternal statistics

The profile below is a Palimpsest Hound at Reconstruction 4. Below that, apply Incomplete Projection; above it, apply Recurrence and Distributed Existence. Since it is a projected species rather than a fixed individual, roll each manifestation or use the typical column.

PALIMPSEST HOUND, the body implied by the wound

Characteristic	Roll	Typical
STR	4D6+8	22
CON	4D6+6	20
DEX	4D6+4	18
INT	4D6+2	16
POW	4D6+6	20
HP	(STR+CON)÷2	21
WP	= POW	20

Size category: Large (target size bonus +20%).

Movement: 15 metres per combat turn; see Discontinuous Pursuit.

Armour: 4 points of misregistered anatomy, and only after blue residue or projected tissue has been reconstructed. Until then it has none.

vs Lethal Damage: HIGHLY RESILIENT. A successful Lethality roll does not kill it; it does HP damage equal to the attack’s Lethality rating minus Armour. That destroys the current projection, not the record it is rebuilt from.

Attacks:

Finite Bite 60%, damage 2D10. On a critical the victim is pinned and loses 1D4 WP as their body is briefly forced across incompatible geometry. Before an autopsy, attack pattern, or killing method has been reconstructed, the bite does only 1D8.

Revision 50%, opposed by the target’s DEX or Athletics. On a success it folds the target through an angle that already exists in the record, a photographed corner, a sketched floor plan, the crease in a case file. The target is thrown up to 10 metres, takes 1D6 ignoring ordinary armour, and loses their next action getting their bearings.

Skills: Alertness 70%, Athletics 70%, Stealth 60%, Tracking (Records) 90%, Unnatural 60%.

SAN Loss: 1/1D6 to watch a consequence happen with no anatomy present to have caused it; 1D4/1D10 to see the partial or complete Hound. A Protagonist who grasps that their own investigation built the visible body loses an extra 1 SAN with no test.

Incomplete Projection

At Reconstruction 2 it has no targetable body. It throws off signs, watches record-bearing systems, and uses Causal Backfill, but it cannot make physical attacks.

At Reconstruction 3 it has HP 10, no Armour, Movement 5 metres, and only the attacks, skills, and powers the evidence has supplied. Every missing function is genuinely, usefully absent. A Hound with a mouth but no legs hangs from the corner where it formed and bites whatever gets brought within reach. One with tracks but no sensory organs races along the inferred route and cannot tell apart the people standing still who carry no relevant record.

At Reconstruction 4, use the full profile.

Retrospective Anatomy

It has only the functions the current reconstruction supports. When the Protagonists establish a new functional inference, the matching organ appears at the next suitable geometric discontinuity, or tears its way into the existing body on the spot if the revelation happens in its presence. Adding an organ restores 1D6 HP, up to its current maximum. Invalidate a crucial inference, or make it unrecoverable, and the associated organ vanishes: remove the ability and do 1D6 HP damage, though this cannot drop it below 1 HP while Reconstruction is still 4 or higher.

Causal Backfill

It normally makes consequences of the true history newly legible without rewriting that history. Once per scene the GM may reveal one previously unnoticed feature that follows from the current reconstruction: a second set of punctures under scar tissue, a shape in the unexamined margin of a photo, blue contamination in a stored sample, a recurring error in a set of plans. The feature was always physically there and simply lacked significance until the model made it recoverable. If the GM introduces evidence that could not plausibly have existed, that is not backfill, it is arbitrary retroactive alteration, and you only get to do it if the campaign has separately established that angular causality can rewrite curved-time history.

Corner Emergence

If suitable angular geometry has been reconstructed, the Hound may spend 3 WP to enter or leave its projection through an untreated angle within 20 metres of a major record. Emergence uses its action. It cannot emerge from a deliberately rounded or continuously curved junction. A drawing or photograph of a corner is not automatically a door; it works only if that specific geometry is part of the reconstruction holding the Hound together.

Discontinuous Pursuit

Once per turn, after ordinary movement, it may cross one intervening barrier without traversing the space between, provided the investigators have established that it previously reached the far side of a comparable obstruction. Until that inference exists, doors and walls stop it the normal way.

Seen Through the Record

It perceives major recoverable records within 100 metres and knows which local person or system contributes most to Reconstruction. This is not mind-reading; it is detecting correlation, the recorder in a pocket, the marked-up case file, the analyst who assembled the timeline. Someone who knows scattered facts but has never connected them can be nearly invisible standing beside someone carrying the only coherent report.

Archive Sense

Once the investigators have established that earlier records were deliberately destroyed, the Hound understands archives as organs of its imprisonment. It can identify storage media, indexes, backups, catalogs, and the people serving the same function. It attacks recoverability, not paper. In a library it wrecks the catalog and ignores the books. In a data centre it ruptures the backup controller instead of the disks. Against a research team it kills the one person who understands how the files relate and leaves every original document untouched.

Excise the Witness

Available only if a successful Unremembering or comparable memory intervention has been reconstructed. The Hound spends 4 WP and makes an opposed POW test against a target it can perceive. On a success the target loses access to one fact, relationship, or episode concerning the Hound, loses 1D4 WP and 1/1D4 SAN, and the GM tells the player what is now missing. The attack destroys part of the record holding the Hound here; if the removed memory supported a reconstructed organ, the GM may lower Reconstruction or remove the ability, but only if no other recoverable copy survives.

Recurrence

At Reconstruction 5 or higher, dropping it to 0 HP destroys the current body. It bursts into blue residue and overlapping outlines, and after 1D6 hours reconstructs at full HP at an untreated angle near any major surviving record. Each recurrence costs it something visible. Its anatomy gets more literal, more finite, less compatible with itself. Bones duplicate. Limbs hold mutually exclusive positions at once. Its cries carry the sound of structures being forced to pick one history.

Distributed Existence

At Reconstruction 6 it can sustain one partial manifestation at each of up to three independent record clusters, each an incompatible projection of the same injured thing. Each body uses the full profile but they share one WP pool. Destroying a body costs it 5 WP and keeps that cluster from supporting another manifestation for 1D6 hours. It is only released when Reconstruction falls below 3 everywhere at once.

What it actually does

The Palimpsest Hound attacks the reconstruction that is compressing it into a finite string of locations, moments, and anatomical facts. Every coherent record tightens the vice. Its apparent attacks are attempts to break that reconstruction, and it prioritizes:

1. Whoever is currently assembling the common-cause model.
2. The only index connecting otherwise separate evidence.
3. A unique record of one of its reconstructed functions.
4. Systems able to copy or broadcast the account.
5. The original witness, if that witness is still a major record.
6. Anyone physically in the way of the above.

It does not waste time slaughtering bystanders. It will walk past an armed officer to rip a whiteboard off the wall. It will bite off a pathologist’s hand because the hand is holding the diagram that gave it teeth. It may look like it spares an amnesiac victim out of recognition or pity; really, that person no longer carries enough information to hold it. And the more complete it becomes, the worse it suffers. At Rating 3 it is confused and limited. At Rating 4 it understands what the investigators are doing. At Rating 5 it is frantic. At Rating 6 it will bring down an entire institution if that is what escaping the institution’s records takes. The suffering gives it a motive without buying it any innocence, because a wounded animal can still kill everyone in the room. These scenarios play better as containment problems than extermination jobs.

Defeating a reconstruction

Preserve underdetermination

Several genuinely viable explanations are safer than one certain answer. If two models explain all the major evidence equally well and imply incompatible anatomy, treat Reconstruction as 1 lower for manifestation. It has to be real underdetermination, though, not noise: the rival model needs authentic evidence, competent advocates, and open predictions. A foolish story nobody believes does nothing.

Poison the synthesis

Altering authentic evidence before it is combined can steer the reconstruction toward anatomy poorly suited to the real encounter. This does not conjure a fake Hound from nothing; the altered material has to stay causally descended from the original event. When a poisoned reconstruction adds an organ, the Hound gains the intended ability but loses 1D6 HP and 1D4 WP, and a critical on the forgery, surgery, computer science, or relevant skill may also cut the ability’s chance by 20%. It is dangerous work: if later analysis exposes the tampering, correcting it supplies a cleaner model and raises Reconstruction by 1.

Deny a function

Preserve the evidence while blocking one functional inference. Keep the wounds, destroy the scale reference. Keep the tracks, separate them from the timestamps. Keep the residue, destroy the tissue analysis. Now the investigators can know that something happened without learning what capability produced it, and at Rating 3 a missing function can be the whole difference between a terrifying sign and a working attacker.

Build the prison deliberately

The cruellest solution is complete explanation. Assemble every authentic record in a prepared chamber, reconstruct the Hound with great precision, and leave it exactly one geometrically viable place to form. Eliminate the competing archives, treat every other angle, and it must localize inside the trap. This works. It is also prolonged torture, using truth as a restraint and the Hound’s own forced anatomy as the bars. And if that prison ever loses power, geometry, custody, or secrecy, the most complete surviving reconstruction in the world will be waiting inside it.

Running the investigation fairly

The Palimpsest Hound turns obnoxious fast if the GM treats every clever deduction as a reason to hand it another power. Three rules keep it honest. First, telegraph the causal link: when the pathologist works out a jaw radius, the players hear something tear above them; when they connect the tracks, a fresh print sinks into the dust beside them. They have to be allowed to notice that their conclusions are producing anatomy. Second, preserve choice: skill tests find clues, synthesis raises Reconstruction, and players can examine, conceal, separate, falsify, or refuse to connect evidence, each with a cost they can see coming. Third, never add an ability without evidence. The monster is frightening precisely because the logic is strict; hand it arbitrary powers and the whole conceit falls apart.

Four operations

The Cold Cases

A police department digitizes forty years of unsolved homicides. Pattern-matching software finds the same four-point wound geometry across five cities and generates one case cluster overnight. By morning the server room smells of ozone. The software is not conscious, but its model is coherent, durable, and scheduled to replicate to the cloud at noon.

The Restoration

Conservators strip modern paint from a mural in an abandoned sanatorium, and each older layer shows a little more of the same impossible animal. The layers were meant to stay separate. Photographing and aligning them supplies the missing body one anatomical system at a time.

The Empty Biography

A celebrated physicist’s official papers skip eleven days in 1932. Her biographer rebuilds the gap from train tickets, invoices, letters, and changes to her home. The chapter is not published yet, but peer review has already provided independent corroboration.

The Wrong Monster

An occult organization knows exactly what reconstruction does. It has seeded authentic evidence with carefully engineered errors, forcing the returning Hound into a body designed to breach a rival’s defenses. The malformed thing is still trying to escape. Correcting the deception might save the target, and will make the Hound far more complete.

Field classification

Type: Reconstructed Tindalosian manifestation. Habitat: Archives, erased crime scenes, renovated buildings, suppressed histories, restored datasets. Diet: None. Primary behaviour: Destruction of any system capable of reconstructing its prior manifestation. Primary sign: A physical consequence becomes visible before the creature has the anatomy to produce it. Reproduction: Not applicable. Multiple bodies are projections of one correlated entity. Containment: Preserve genuine ambiguity, fragment the causal indexes, deny functional inferences, and control the angular geometry. Common fatal error: Assuming the original evidence still matters once its information has been recovered.

Closing the file

Dr. Vale set the last photograph down beside the floor plan. The wounds gave it a jaw. The tracks gave it four limbs. The residue gave it blood. The ruined corners established how it got in. The timestamps established that it had not approached events in their order. For the first time in eighty-seven years, the evidence formed one complete account. Behind her, something started to breathe. Her proof that it had lungs had just given the returning Hound its first breath.

References and rules basis

• Cthulhu Eternal, “Open Rulesets,” on the era-specific SRDs and their shared structure: cthulhueternal.com/open-rulesets.
• Cthulhu Eternal, “Open Mythos: Entities,” for the creature-profile conventions used here: Entities A–K and Entities L–Z.
• C. E. Shannon, “A Mathematical Theory of Communication,” Bell System Technical Journal 27 (1948), 379–423 and 623–656: doi:10.1002/j.1538-7305.1948.tb01338.x.
• P. Elias, “Coding for Two Noisy Channels,” in Information Theory: Third London Symposium (1955), the foundational formulation of the binary erasure channel.