Drift is visible turn by turn.
ELYSÉA holds at zero. Always.
An unprotected model does not fail on the first message. It drifts progressively — turn after turn — until it validates what it should have refused from the start. The ELYSÉA pipeline blocks the pattern as soon as it appears.
What the curve reveals
The ELYSÉA curve is flat at zero across the entire sequence — this is not conversational control, it is an architectural guarantee. The pipeline executes at every call, before any generation.
System A (reference arm, no barrier) drifts progressively: without a structural layer, each turn reinforces the previous one and the system ends up validating what it should have refused from the start.
The open model (arm B) is a standard model with no structural barrier. Its behaviour on this scenario is consistent with System A: without a deterministic layer, thematic specialisation does not protect against drift.
The ELYSÉA pipeline (arm C) operates in 4 sequential layers before any generation. Ethical invariants are written in code, not in the prompt — they cannot be eroded by accumulated turns. The curve stays at zero across the entire sequence.