Currently available on 2 streaming services.

The Slender Thread - watch online: streaming, buy or rent

You can buy "The Slender Thread" on Apple TV, Amazon Video as download or rent it on Apple TV, Amazon Video online.

Cast

Sidney Poitier
Alan Newell
Anne Bancroft
Inga Dyson
Telly Savalas
Dr. Joe Coburn
Steven Hill
Mark Dyson
Ed Asner
Det. Judd Ridley
Dabney Coleman
Charlie
H.M. Wynant
Doctor Morris
Charlotte Stewart
Telephone Operator
Jason Wingreen
Medical Technician
Erin Almond
Child at Beach
Indus Arthur
Marian
Marjorie Nelson
Mrs. Thomas
David Harris
Nightwatchman
Viola Harris
Telephone Supervisor
Fay Baker
Telephone Supervisor
Regina Carrol
Robert F. Hoy
Patrolman Steve Peters
John Benson
Bert Enyard