The engine always honored the stone — its bearer casts through exactly one wall or door — but the targeting shadow never did: sightedCellsFor kept every square behind a wall dimmed, so the aid told the bearer the stone wasn't working. The sighted set now retries each unseen square with a single edge removed, mirroring casterLos; the automaton shares the function, so bots see through their stones too. Two tests pin the engine ruling and the client parity. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015RCWSTnb1KYTPyL4GmhGnF