“Warner Oland vs. Boris Karloff in…” says the title card of this movie, easily one of the strongest entries in the long-running Charlie Chan mystery series, thanks to setting, cast, and resolution. Karloff plays an amnesiac opera singer who escapes from a lunatic asylum after recovering his memory that someone — presumably his then-wife — had locked him in a burning theater to meet his doom. He makes his way to the theater where his ex-wife will be performing in the opera Carnivale (written by Oscar Levant), which had been contained his greatest role, as Mephisto. Also at the theater are the ex-wife’s current husband (the show’s producer), her lover and his wife, and the police (including Chan), who are there because the diva has received a death threat. Murder follows.

Karloff is appealing and sympathetic as usual, and the mystery is effective as well. Keye Luke as son Lee proves an able helper in his father’s investigation, too, while providing some comic relief (as does cop William Demarest).

  Recommended. Otto finds this one pleasing enough to relax.