Maureen O'Sullivan

Hugo Hackenbush (Groucho Marx) is a veterinarian who masquerades as a lead doctor at Standish Sanitarium to aid the wealthy patient Emily Upjohn (Margaret Dumont). In order to save the financially failing sanitarium and its beautiful owner, Judy Standish (Maureen O'Sullivan), Hackenbush, employee Tony (Chico Marx) and jockey Stuffy (Harpo Marx) must find ingenious ways to help Gil Stewart (Allan Jones) and his inept racehorse, Hi-Hat, win the big race.

The recently divorced Clyde Wynant discovers that his new girlfriend has stolen $50,000 and is carrying on with other men. Not long afterward, he disappears. Anxious to locate her father, Wynant's daughter goes to private detective Nick Charles for help.