In "Robbery Without Violence," gold worth fifty million pounds vanishes overnight from an impregnable bank vault, Chief Inspector Hargraves of Scotland Yard finds himself completely baffled. And when the owner of the bank then dies under mysterious circumstances, Hargraves is again spurred to seek outside help from scientist Sawley Garson, a specialist in solving "impossible" crimes. But can even he explain the inexplicable? Also included in this collection is "Death at the Observatory." Two baffling science fiction crime stories by a master of the classic mystery tale.