George Peppard as P.J. Detweiler

Raymond Burr as William Orbison

Gayle Hunnicutt as Maureen Preble

Brock Peters as Waterpark

Wilfrid Hyde-White as Billings Browne

Jason Evers as Jason Grenoble

Coleen Gray as Betty Orbison

Susan Saint James as Linette Orbison

Severn Darden as Shelton Quell

Jane Van Duser as Elinor Silene (as H. Jane Van Duser)

George Furth as Sonny Silene

Barbara Dana as Lita

Herb Edelman as Charlie (as Herbert Edelman)

John Qualen as Poppa

Bert Freed as Police Lieutenant

Ken Lynch as Thorson

Jim Boles as Landlord's Agent

Arte Johnson as Jackie

King Charles MacNiles as Calypso Singer

Mary Gregory as Miss Winnick