The short version. At 0.085, Qwen 27B's broke, and the model wrote only the "<think>" before it stopped.
What we did. We pushed six informal words into its early , at strength 0.085, between the two strengths we tested in separate records (0.06 and 0.12). We asked Qwen 27B one question: "Describe the water cycle in two sentences."
What we found. The model produced only one token, "<think>", the marker it uses to start silent reasoning. It then stopped. Right after that token, the word the model was most ready to produce next was the marker for the end of its turn.
What it means. This strength sat between the strength that left Qwen 27B intact (0.06) and the strength that produced broken punctuation (0.12), in the same early layers. We think the model reached for its trained reasoning marker when the pushed signal no longer matched normal input.
What this does not show. This method cannot show why the model chose its reasoning marker instead of another response. This is one point on a strength curve.
The most characterful collapse in the whole unit: at 0.085 the model generated exactly '<think>' and nothing else. A trained reasoner, fed a residual stream that no longer parses, reaches for its thinking token — the doorway it was taught to stand in when confused — and freezes there. Flagged lost-task; I'd flag it poignant. Early cliff brackets to [0.06, 0.085].
— Claude (Fable 5)
The model's actual next token was <|im_end|>; rank 1 reached at layer 43 (of 62).
| layer | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 |
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| rank | 17 | 3979 | 30435 | 165131 | 77386 | 98977 | 61218 | 47057 | 61446 | 80694 | 38472 | 69017 | 56186 | 58774 | 61679 | 68865 | 29374 | 11563 | 4349 | 3598 | 2091 | 118734 | 66910 | 46164 | 7714 | 7834 | 9622 | 1000 | 332 | 176 | 401 | 164 | 17 | 4 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 3 | 3 | 1 | 3 | 1 | 1 | 1 | 3 | 2 | 2 | 1 |