Think Fast, Mr. Moto began a popular mystery series that spawned eight installments in total. It's pretty clearly an attempt to ride the coattails of the immensely popular Charlie Chan series, but Mr. Moto rises well above the level of a cheap copycat and establishes its own distinct identity.

Part of the appeal of Mr. Moto is that we never really learn who he is. We know instinctively that he's a hero, because who else could be so sharp and cunning about hunting down the badguys? So we rally behind Mr. Moto and cheer him on, inasmuch as maybe we're intimidated by him at times. There's a scene in Think Fast, Mr. Moto where he discovers the identity of a spy working for a crime ring, and Moto dispatches him with the same ruthless efficiency the badguys themselves might use.

Elaborate disguises and rough-and-tumble judo were popular trademarks of the series. Modern moviegoers are more savvy about both than audiences of the day, but it's not hard to imagine how fresh the material was in the late thirties. The spirit of fun and the lure of a good mystery are still potent, however. These are B-movies, but they're good B-movies.