Though overlong even for a Hayley Mills vehicle, That Darn Cat is an expert blend of laughs and suspense. The eponymous feline is D.C., a Siamese belonging to sisters Hayley Mills and Dorothy Provine. One evening, D.C. comes flouncing home with a lady's wristwatch attached to her neck. The watch contains an unfinished plea for help scribbled on its back, written by Grayson Hall, a bank teller held captive in a neighboring house by robbers Neville Brand and Frank Gorshin. Mills and Provine contact the FBI, who send agent Dean Jones (who's allergic to cats) to investigate. In their efforts to locate and rescue Hall and capture the crooks, Jones and the two sisters embark upon a series of slapstick misadventures involving an unending stream of top character actors. The highlight is a lengthy sequence at the drive-in movie theatre managed by ulcerated Richard Deacon. That Darn Cat is based on Undercover Cat, a somewhat more serious suspense novel by The Gordons.