The second of Universal's "modernized" Sherlock Holmes films pits the Great Detective (Basil Rathbone, of course) against that "Napoleon of Crime," Professor Moriarty (Lionel Atwill). Surpassing his previous skullduggery, Moriarty has now aligned himself with the Nazis and has dedicated himself to stealing a top-secret bomb sight developed by expatriate European scientist Dr. Franz Tobel (William Post Jr.). Before being kidnapped by Moriarty's minions, Tobel was enterprising enough to disassemble his invention and distribute its components among several other patriotic scientists. Racing against the clock, Holmes and Dr. Watson (Nigel Bruce) try to stem the murders of Tobel's colleagues and prevent Moriarty from getting his mitts on the precious secret weapon. The now-famous climax finds Holmes playing for time by allowing Moriarty to drain all the blood from his body, drop by drop ("The needle to the last, eh Holmes?" gloats the villain). Dennis Hoey makes his first appearance as the dull-witted, conclusion-jumping Inspector Lestrade. Constructed more like a serial than a feature film, Sherlock Holmes and the Secret Weapon (based loosely on Conan Doyle's The Dancing Men) is one of the fastest-moving entries in the series; it is also one of the most readily accessible, having lapsed into public domain in 1969.
by Hal Erickson synopsis