Pale Horse Protocol is the Bureau's operational standard for the containment of anomalies that alter the fundamental rules of reality — space, time, causality, or the persistence of matter. It governs phenomena near which the framework reality ordinarily runs on becomes locally unreliable. The protocol is binding on all personnel assigned to a PALE HORSE-classified case, and on any personnel who encounter an unclassified anomaly exhibiting the indicators set out in §2.

Pale Horse Protocol applies to anomalies whose primary action is upon the fundamental structure of reality: violation of physical law, distortion of space, manipulation of time or causality, or the cessation or alteration of matter. Assignment is computed from the hazard weight matrix (Compendium §8); a hazard profile weighted toward the Dimensional (D), Temporal (T), and Metaphysical (M) categories resolves to PALE HORSE.

An anomaly is handled under this protocol from the moment its indicators are recognized in the field, in advance of formal classification and irrespective of provisional control code. Where the computed protocol does not match operational reality, assignment may be overridden in the case header with justification recorded in the Containment Protocol section.

Under Pale Horse Protocol, the rules do not hold.

The danger is not a force that acts upon personnel but the local failure of the framework reality runs on — space, time, causality, the persistence of matter. The tools used to assess a situation are themselves part of that framework, and near the anomaly they may report falsely. Three assumptions govern all handling under this protocol:

1. Measurement and the senses are not trustworthy. Inside the affected zone, distance, duration, and sequence may be locally invalid. A reading is confirmed only against a reference outside the zone.
2. Effects are unpredictable. A reality-violation generates inconsistent and novel effects that cannot be enumerated in advance. The Bureau prepares contingencies for the unanticipated rather than predictions of the specific.
3. Intervention propagates. Acting on a reality-violation can displace or amplify it rather than resolve it. A containment action is assumed to have consequences beyond its target until modeled otherwise.

The following measures are to be held in memory and applied without reference to documentation. A field agent encountering an anomaly that presents PALE HORSE indicators — distortion of space, time, causality, or the persistence of matter — observes them before and during first contact.

1. Distrust your instruments and your senses. Distance, duration, and sequence may be locally invalid. Confirm any reading against a reference outside the affected zone.
2. Establish a boundary before you enter. Mark the line at which effects begin and do not cross it to investigate. Bounding the zone is the first containment act.
3. Do not assume cause precedes effect. Treat events occurring out of sequence, at a distance, or before their trigger as the anomaly — not as instrument error.
4. Change nothing you cannot model. Intervention can displace or amplify a reality-violation, and a containment action may take effect elsewhere. Assume cascade.
5. Do not expect to hold it. Aim to stabilize, suppress, or bound the anomaly — or to observe and accept it — not to capture it.
6. Account for the people, not just the site. Anyone who crossed the boundary may return displaced in time or duplicated. Maintain a headcount.

CRITICAL — Time inside the affected zone is not assumed equal to time outside it; personnel do not enter alone, and none are presumed lost until accounted for against an external clock.

Containment under Pale Horse Protocol is exotic and, more often than not, indirect. A reality-violation cannot be placed in a box; the Bureau maintains a condition that suppresses it, bounds the zone in which it is safe to operate, or — where the effect is null or acceptable — observes and accepts it.

Posture matched to threat. Containment posture is set by the anomaly's actual threat, not by its strangeness. An uncontainable but harmless reality-violation is placed under bounded observation rather than subjected to futile containment effort; a localized and benign anomaly may be held by operating restriction alone.

Stabilization and boundary. Where the anomaly is active, containment maintains the condition that suppresses it and the boundary that limits exposure to it. The boundary is set short of the depth, duration, or proximity at which personnel are lost; it is reviewed against incident data, not relaxed by default.

Cascade assessment. Any major containment action at a reality-violation site requires assessment of its effect on other such sites. A containment action is assumed capable of displacing the violation toward the nearest viable focus until demonstrated otherwise.

Causality monitoring. The affected zone is monitored for effects appearing before their cause, out of sequence, or at a distance — the early indication that the local framework is slipping. Contingency planning anticipates unpredictable outcomes rather than a specified failure.

Catalogued effects. Where a case manifests an effect recorded in the Anomalous Symptoms Repository (REP-600-11), the effect is referenced by its catalogue entry rather than re-described.

Displacement accounting. Personnel entering an affected zone are tracked against an external reference of time and number. No personnel enter alone where temporal or spatial displacement is possible. Personnel returning from the zone are reconciled against the external clock before being cleared, and are not presumed lost until so reconciled.

Screening and exposure. Exposure is time-limited and rotated. Personnel are screened under the Cognitive Screening Form (SC-900-05) where the anomaly acts on perception or memory, and evaluated following exposure to causal or temporal effect.

Treatment. Affected personnel are treated under PR-400-20 (Memory Reconfiguration Procedures) and PR-400-21 (Personality Anchoring Procedures) as indicated.

Where standing containment is failing — the violation expanding beyond its boundary, escalating in frequency, or resisting the condition that suppresses it — personnel escalate immediately through the case Handler or Site Director. No major containment action is taken at a reality-violation site without cascade-vector assessment; an intervention may stabilize one site and destabilize another.

Attempted or imminent containment failure of a PALE HORSE anomaly is addressed by Contingency CY-400-84 "PALE HORSE-TERMINUS". Measures following successful containment failure are addressed by Contingency CY-400-94 "PALE HORSE-EXCIDIUM". Contingency content is held at Site Director level and above; personnel below that level are required only to know that the contingencies exist, and that the response to attempted failure is not the same as the response to successful failure.

The following records reassessments of this protocol arising from specific cases. Routine revisions logged under the Documentation Specialist review cycle (Form REQ-000-02) are not reproduced here.

• 1945 — Containment displaces. Following CASE-0092, the first invocation of this protocol's TERMINUS-tier contingency stabilized one dimensional-instability site and triggered an immediate cascade at the nearest viable focus, requiring a second deployment within days. Cascade-vector assessment was made mandatory prior to any major containment action at a reality-violation site.
• 1962 — Some violations are uncontainable. Following CASE-0002, the cessation of years of failed physical-containment effort established that a reality-violation producing null or acceptable effect is placed under bounded observation rather than subjected to containment. Posture is set by threat, not by strangeness.
• 1987 — Operating-rule containment. Following CASE-1870, a localized and benign reality-anomaly was established as containable by operating restriction alone, and the combination or exceeding of its parameters as a source of unpredictable secondary effects. The relevant prohibitions were codified as operating rules.
• 2011 — Bound the zone; no solo movement. Following CASE-1212, the recovery of personnel remains aged far beyond external elapsed time, together with documented expedition duplication, established a fixed access boundary short of the depth at which personnel are lost and a standing prohibition on solitary movement within the affected zone.