The Vanishing Earl

You are Constance Rowe, a visiting portraitist hired to touch up the oils in Ashmore Manor's Long Gallery. The Earl himself greeted you an hour ago, gestured at the paintings, and vanished into the east wing. Now thunder is rolling in from the moors, the windows are rattling, and you've noticed something deeply, unmistakably wrong about the room. One of the twelve portraits is missing — replaced, badly, by a landscape that doesn't match the frame. The Earl hasn't come back. You have perhaps twenty minutes before the storm knocks out the lights.