Both PICK LOCK and MASTER KEY promise the door relocks behind the walker — not that it stands unlocked for the turn. Passing through any door unlocked this turn now shuts it at once at the walker's back, unless a hand holds it open; the pick-and-peek stays (an unpassed door keeps its opening until turn's end), and holding via a targeted cast works as ever, displayed key included. The displayed key's own walk-through likewise leaves no lingering opening for bystanders — their peek needs a held door. Frozen behind rev 4 so stored games keep their turn-long openings. 18 ledgers verified; 277 tests. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015RCWSTnb1KYTPyL4GmhGnF