'Deceived by Flight' by Anthony Minghella (ITV, tx. 18/1/1989)

The alumni of an Oxford college return to play the annual old boy's cricket match. They include Morse's old friend, Anthony Donn, who is in a state of emotional crisis when they meet, enigmatically quoting Buddhist parables he has found in a book belonging to his wife. Meanwhile Morse attends a crime scene at a left-wing bookshop, where the staff have been killed in an arson attack.

Donn calls Morse but he is unable to take the call as he is questioning the arson suspects. Donn is found dead, apparently having electrocuted himself, although a gun is found in his luggage. Lewis notices a couple spying on the murder scene through binoculars. Donn's wife Kate, a radio presenter, is told of the killing and later collapses.

Morse meets the rest of the cricket team, including womaniser Cranston and the organiser, failed inventor Roly Mitchell, an old college friend of Morse. Together they hatch a plan for Lewis to pose as a college porter and infiltrate the cricket team.

The spying couple are the Fosters, who arouse Lewis's suspicions. Morse interviews Mrs Foster, who flirts with him, inviting him to see the cricket match. The opposing team arrives at the college, captained by Roly's nephew. Lewis follows Mr Foster to the pavilion but is knocked unconscious.

Recovering, Lewis plays in the cricket match. Soon after Lewis takes the wicket of Roly's nephew, the murdered body of Mr. Foster is found in the pavilion. Mrs. Foster confesses that she and Foster were not in fact married but were officers for Customs and Excise, investigating a drug ring that appeared to be linked to the cricket team's foreign tours. She admits her flattery of Morse was purely professional.

Morse visits Kate Donn and finds the Buddhist book on her shelves, with a romantic inscription. Morse and Lewis wait at Dover docks, where the cricket club are due to catch a ferry. Morse suddenly realises that heroin shipments are hidden in Roly's wheelchair. When arrested, he blames bitterness at his failure and disability. Foster had been killed by Roly's nephew, who is also arrested. As Kate Donn presents her radio show, Morse enters the studio and arrests her. She had been having an affair with Cranston. Donn had found out and was hoping to kill Cranston, but she had murdered him without realising that this was his intention. Cranston had inscribed the book, hence Donn's references to it. Morse had mistakenly thought both strands of the case were connected but in fact their link was entirely coincidental.