The timber-framed Queen’s House that nestles in a corner of the Tower of London’s Inner Ward is a little-known building. A top-floor room known as the Council Chamber contains an extraordinary wall-mounted monument erected in 1608 that commemorates the failure of the Gunpowder Plot. Alongside it is a carved portrait of King James I in half relief. This article explores these two remarkable objects for the first time and argues that the undated portrait relief may be contemporary with the monument, and may be a previously unrecognized carving by the King’s Master Carver Maximilian Colt (fl. 1595–1645). The article further suggests that the Council Chamber was created as a room in which to interrogate prisoners, and argues that the portrait relief and the monument were part of a carefully designed interior scheme that was intended to act as a tool of interrogation.