The famed detective Charlie Chan(Warner Oland) is on board a steamer when a prominent horse breeder is found stomped to death and possibly by his own horse. When Chan investigates he discovers his friend may not have been killed by his horse after all, but actually a ring of ruthless gamblers. Number One Son Lee(Keye Luke)helps prove that the smallest clues lead to the biggest answers. Charlie and son will have to match wits with kidnapping gamblers. The races at Santa Anita make a busy backdrop for murder gone bad. H. Bruce Humberstone directs this caper that also features: Helen Wood, Paul Fix, Gloria Roy, Thomas Beck , George Irving and Robert Warwick.