One of the greatest locked-room murder mysteries of all time, hailing from 1938, returns to baffle a new bevy of armchair detectives. James Answell, visiting his father-in-law Avery Hume in his locked study, has the misfortune to wake up from a drugged-Whisky swoon to find his host dead, skewered with an arrow. He is, of course, prime suspect. After setting up this devilish scenario, unravels an ingenious courtroom thriller, in which the razor-sharp amateur detective (and barrister) Sir Henry Merrivale stars in all of his outlandish glory and the mystery of the 'Judas Window' is revealed.