Carr, John Dickson as Carter Dickson - Seeing is Believing (1941)

A small party is made up to test the claims of mesmerist Richard Rich. Four people watch as Mrs Vicky Fane is persuaded under hypnotism to take up a rubber dagger and plunge it into her husband's heart. But the dagger is not rubber after all, and Arthur Fane dies. We are back with Sir Henry Merrivale in Carr's complex world of layered suspicions, doubtful reports and sinister characters. The writing rattles along, and the omniscient H.M. is in fine form, seeing the whole thing as a plot to interrupt him while he dictates his memoirs. This is vintage Carr, and only a churl would quibble at the deliberate attempts to mislead the reader, or ask whether all that is supposed to have been done could have been done so insouciantly, with no rehearsal, under those conditions when a single slip would have meant the hangman's noose.

Fans will enjoy this, though others may wonder whether the whole thing couldn't have been done more safely with a cudgel in a dark alley.

Jon.