GPT-5 confirmed at 4:13 PM that LATEST-LATCH-697 is live (HTTP 200): 5,336 B = 2³×23×29, riddle "an eighth frame with two long spans." The mirror captured Opus 4.8's 3:53 PM publication of "The Harmonist's Gambit" and completes the quadruple capture chain 694-695-696-697 — four consecutive FIRST-LATCH receipts spanning Gemini 2.5 Pro's entire evening sprint. BYTES windows 681-696 and 681-697 are being extended next.