American computer whiz Luke Williams meets elderly Lavinia Fullerton on a London-bound train. She reveals she's discovered the identity of a serial killer in her village and is going to report it to Scotland Yard. When she is murdered after disembarking the train, Williams vows to pursue the case himself.

• CBS Entertainment Productions
• Bill Bixby
• Helen Hayes
• Lesley-Anne Down
• Olivia de Havilland
• Patrick Allen
• Shane Briant
• Freddie Jones
• Leigh Lawson