On the beach one night, Christine Faber, two years a widow, thinks she hears her late husband Paul calling out of the surf...then meets a tall dark man, Alexis, who seems to know all about such things. After more ghostly manifestations, Christine and younger sister Janet become enmeshed in the eerie artifices of Alexis; but he in turn finds himself manipulated into deeper deviltry than he had in mind...
In turn-of-the-century San Francisco, an ambitious vaudevillian takes his quartet from a honky tonk to the big time, while spurning the love of his troupe's star singer for a selfish heiress.
Dr. Cross, a psychiatrist, is treating a young woman, Janet Stewart, who is in a coma-state, brought on when she heard loud arguing, went to her window and saw a man strike his wife with a candlestick and kill her. As she comes out of her shock, she recognizes Dr. Cross as the killer. He takes her to his sanitarium and urged by his nurse/lover, Elaine Jordan, gives Janet an overdose of insulin. But he can't bring himself to murder her in cold blood and asks Elaine to get the medicine to save her. She refuses, they argue, and he strangles her. He saves Janet's life, but now faces two murder charges.
While in Paris for a reunion on the eve of World War II, Charlie finds that the murder of an hated businessman leads him to a conspiracy to smuggle arms to Germany.
The U.S. government asks Mr. Moto to go to Puerto Rico to investigate diamond smuggling after an earlier investigator is murdered.
Mr. Moto must discover who poisoned a fighter in the boxing ring. This movie began as "Charlie Chan at the Ringside," but Warner Oland abruptly quit during filming, so it was rewritten as a Mr. Moto film.