On the set of a popular daytime soap opera 'Mile High', actress Kris Buckner is being forced off by co-star Mark Stratton. When she says that she'll 'kill him before she leaves the show', she makes herself the prime suspect when Stratton is murdered by someone poisoning him. As an old friend, Perry Mason comes to the help of Kris and agrees to defend her. Meanwhile Ken goes in search of information with the help of fan of the show.

Raymond Burr
as Perry Mason

Barbara Hale
as Della Street

William R. Moses
as Ken Malansky

Linda Dano
as Sandra Drake

Stuart Whitman
as Alex Straub

Genie Francis
as Kris Buckner

Sean Kanan
as Mark Stratton

Kurt Soderstrom
as Guard

Mark Boudler
as Officer Jolly (uncredited)

Wendelin Harston
as Ticket Clerk