Trailer
Images
 | Bill Bixby as Prof. Luke Williams |
 | Helen Hayes as Lavinia Fullerton |
 | Lesley-Anne Down as Bridget Conway |
 | Olivia de Havilland as Honoria Waynflete |
 | Patrick Allen as Maj. Horton |
 | Shane Briant as Dr. Thomas |
 | Freddie Jones as Const. Reed |
 | Leigh Lawson as Jimmy Lorrimer |
 | Jonathan Pryce as Mr. Ellsworthy |
 | Ivor Roberts as Vicar |
 | Trevor T. Smith as Rivers |
 | Anthony Valentine as Abbot |
 | Timothy West as Lord Gordon Easterfield |
 | Carol MacReady as Mrs. Pierce |
| Diana Goodman as Rose Humbleby |
| Frederick Wolfe as Avery |
 | Patrick Wright as Attendant |
| Writing | |
| Agatha Christie | Novel |
Directing | |
| Claude Whatham | Director |
Writing | |
| Carmen Culver | Teleplay |
Production | |
| Stan Margulies | Producer |
| David L. Wolper | Executive Producer |
Sound | |
| Gerald Fried | Music |
Camera | |
| Brian Tufano | Director of Photography |
Editing | |
| David Newhouse | Editor |
Art | |
| Ian Whittaker | Art Direction |
| Ann Mollo | Set Decoration |
Costume & Make-Up | |
| Joan Carpenter | Hairstylist |
| Barry Richardson | Hairstylist |
| Ernest Gasser | Makeup Artist |
| Eddie Knight | Makeup Artist |
