'Sheer luck,' Sigerson Holmes derisively tags his more famous older brother. Sherlock nevertheless delegates a blackmail case involving a soubrette (Kahn) to young Sigi (Wilder),while he himself concentrates on the more pressing investigation of the theft of state documents from the Foreign Secretary. The cases become entangled, however, when it transpires that the soubrette's father is the Foreign Secretary (Le Mesurier) and that her fiancé, the opera singer Gambetti (DeLuise), wants to obtain papers in papa's safe. Writer/director Wilder spins a very tangled tale, and production designer Terry Marsh has gone to town on the excessively cluttered 1890s sets, but there's a magnificent on-stage climax, when, during a production of The Masked Ball, documents are due to change hands and the drugged chorus progressively collapses. Hit and miss, with plums picked from all chapters of the comic handbook, and plenty of innocent lavatory humour. Kahn and DeLuise shine among the strong ensemble.