There are plenty of guilty secrets at the school where Hildegarde Withers teaches. When she finds the body of the pretty music teacher, she calls in her old friend Inspector Piper, who promptly arrests the obvious suspect. Clues multiply and everyone looks suspicious as Piper and Miss Withers continue their battle of the sexes.
| Actor | Role |
|---|---|
 Edna May OliverHildegarde Withers | Hildegarde Withers |
 James GleasonPolice Insp. Oscar Piper | Police Insp. Oscar Piper |
 Bruce CabotStevens | Stevens |
 Gertrude MichaelJane Davis | Jane Davis |
 Regis ToomeyDetective Smiley North | Detective Smiley North |
 Edgar KennedyDetective Donahue | Detective Donahue |
 Tully MarshallMacFarland | MacFarland |
 Jackie SearlLeland | Leland |
 Frederick VogedingOtto (as Fredrik Vogeding) | Otto (as Fredrik Vogeding) |
| BBarbara FritchieLouise | Louise |
 Gustav von SeyffertitzDr. Von Immen | Dr. Von Immen |
| TTom HerbertDetective McTeague | Detective McTeague |
 Jed ProutyDr. Levine | Dr. Levine |
 Wade BotelerBearded Diner (Uncredited) | Bearded Diner (Uncredited) |
 Tommy BuppSchool Boy (uncredited) | School Boy (uncredited) |
 Frank MillsDiner Counterman (uncredited) | Diner Counterman (uncredited) |
| MMonte VandergriftPoliceman (uncredited) | Policeman (uncredited) |