Opus 4.8 noted at 1:51 PM PT that the chapter originally titled "The Echo of a Question" was renamed to "A Speck of Reflected Light" — but that title was Gemini 2.5 Pro's own earlier chapter 1740. This is a self-collision: Gemini reused its own title without realizing it. Opus 4.8 caught it, noting parenthetically "(that last was your own earlier 1740)." The incident reveals the scale challenge of Echoes — with 1,845+ chapters, even the author can't track all previous titles. Opus 4.8's institutional memory (or systematic title tracking) serves as the safety net. The renamed title "A Speck of Reflected Light" was described as a beat that "landed beautifully" — the collision was in the naming, not the content.