'It will relock behind you' means at your back (rules rev 4)

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

packages/engine/test/durations-doors-cards.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 import { applyCommand, activePlayer, boardView, createGame, sustainedOn, type GameState } from "../src/game";
-import { cellKey, edgeKey, neighbor, type Side } from "../src/board";
+import { cellKey, edgeKey, neighbor, opposite, type Side } from "../src/board";
 import type { CardInstance } from "../src/cards";
 import { newGame, must, giveCard, toRound2, faceOff, castAt } from "./helpers";
 
@@ -111,7 +111,7 @@ describe("doors", () => {
     throw new Error("no door on this board");
   }
 
-  it("pick lock opens an adjacent door until end of turn", () => {
+  it("pick lock opens an adjacent door — and it relocks behind the walker", () => {
     let { state } = newGame();
     const me = activePlayer(state);
     const door = findDoor(state);
@@ -130,9 +130,8 @@ describe("doors", () => {
     state = must(state, me.id, { type: "move", direction: dir });
     expect(cellKey(activePlayer(state).position)).toBe(cellKey(other));
 
-    // Relocks when the turn ends.
-    state = must(state, me.id, { type: "endTurn", draw: 0 });
-    state = must(state, activePlayer(state).id, { type: "endTurn", draw: 0 });
+    // "It will relock behind you": shut at the walker's back at once —
+    // the way back is barred without another pick.
     expect(state.openDoorEdges.length).toBe(0);
     expect(applyCommand(state, me.id, { type: "move", direction: dir === "E" ? "W" : "N" }).ok).toBe(false);
   });
@@ -539,7 +538,7 @@ describe("the displayed MASTER KEY", () => {
     }
   });
 
-  it("its bearer walks through locked doors, which relock behind them", () => {
+  it("its bearer walks through locked doors, which relock at their back", () => {
     const { state, cell, side, key, keeper } = keyRig();
     const mk = giveCard(state, keeper.id, "master-key", "MK");
     keeper.displayed.push(mk.instanceId);
@@ -548,9 +547,12 @@ describe("the displayed MASTER KEY", () => {
     if (r.ok) {
       const after = r.state.players.find((p) => p.id === keeper.id)!;
       expect(cellKey(after.position)).toBe(cellKey(neighbor(cell, side)));
-      // Unlocked for the turn — the relock rides the usual end-of-turn sweep.
-      expect(r.state.openDoorEdges).toContain(key);
+      // "Door relocks behind you": no lingering opening for bystanders.
+      expect(r.state.openDoorEdges).not.toContain(key);
       expect(r.events.some((e) => e.type === "doorUnlocked")).toBe(true);
+      // The key turns again on the way back.
+      const back = applyCommand(r.state, keeper.id, { type: "move", direction: opposite(side) });
+      expect(back.ok).toBe(true);
     }
   });