Apollo

Late July 1969, and the whole country is looking up at the sky, waiting for Apollo 11 to land on the moon. Morse's welcome to Castle Gate CID is less than warm, and his attention is promptly pulled from the heavens to something far closer to home: the deaths of a promising young astrophysicist and his girlfriend, which look on first inspection like a tragic drunk-driving accident.

The clues do not hold up. Morse enlists the help of Thursday, injured in a stakeout gone wrong led by DCI Box, and the two of them go hunting through some of the strangest corners of late sixties Oxfordshire: the artificial glamour of a studio producing a science fiction puppet show, the esoteric calm of a New Age institute, and a "swingers" party where nobody is quite who they seem. Each stop peels back another layer, and the neat accident story comes apart at the seams.

There is a lovely irony in the whole thing. The world's attention is fixed on the stars, and Morse is down on the ground chasing a killer who never left the atmosphere.

Russell Lewis wrote it, and Shaun Evans directed it, which is a pleasure to note for a man best known for standing in front of the camera. Evans also stars, with Benjamin Wainwright as Professor Adam Drake, Oliver Chris as Dr Elliot Wingqvist, Sargon Yelda as Dr Larry Humbolt, Sasha Willoughby as Flora Humbolt, Sophie Winkleman as Isobel Humbolt, Sara Vickers as Joan Thursday, Alison Newman as Viv Wall, Matthew Cottle as Jeff Slayton, and Michael Parkhouse as the TV Anchor.

The puppet show, the New Age institute and the swingers party give the investigation a wonderful run of period oddity, and the episode keeps a straight face throughout, which is the correct choice. Thursday, working injured, is the anchor while Morse does the legwork.

The moon landing works as a ticking clock rather than decoration, and the episode proves that some mysteries stay stubbornly close to home.