Hot on the heels of his starring turn in The Mad Doctor of Market Street, Lionel Atwill was top-billed in another chiller-diller, The Strange Case of Dr. Rx. Somebody has been going around murdering known criminals who've escaped prosecution thanks to crooked lawyer Dudley Crispin (Samuel S. Hinds). That someone has also left a calling card at the site of each murder, signed "Dr. Rx." Private eye Patric Knowles suspects at first that the elusive murderer is sinister Lionel Atwill, whose "red herring" status is so obvious from the outset that his character name is Dr. Fish! Before the actual killer's identity is revealed, the audience is kept awake by the comic antics of Mantan Moreland and Shemp Howard, both of whom are far funnier than their material.