Mortimer Brewster is living a happy life: he has a steady job at a prominent New York newspaper, he’s just become engaged, and he gets to visit his sweet spinster aunts to announce the engagement. Mortimer always knew that his family had a bit of a mad gene -- his brother believes himself to be Teddy Roosevelt and his world is turned upside down when he realizes that his dear aunts have been poisoning lonely old men for years! When Mortimer’s maniacal brother, Jonathan (who strangely now resembles Boris Karloff), returns on the night that the aunts were planning to bury the newest victim, Mortimer must rally to help his aunts and protect his fiancé -- all while trying to keep his own sanity as well.