Towers of Silence (1)

Series five opens somewhere unexpected: an Arizona scrapyard, where a disused airliner has been parked in the desert for six years, mummifying one of its passengers. A body that spent years drying out at 40,000 feet's worth of heat, found by whoever strips old planes for a living. It's a striking image, and the show knows it.

The mutilations on the desert mummy match those on another body, this one found in a water tower back home. That's the hook. Two victims, two containers, one killer with very particular habits, and between them a trail leading to an armed robbery at Heathrow six years earlier plus a murder from around the same time. The cold case squad's remit suddenly stretches across an ocean, which suits it fine. Nobody here has ever respected a border when there's a body on the other side of one.

There's turnover at the office too. Two new members join: DS Andrea Stephenson, arriving alongside DS Amelia Silver, and Dr Felix Gibson, the new resident "mad scientist" taking the forensic seat. Fresh blood always reshuffles the dynamics, and half the pleasure of a season opener is watching the newcomers find their footing against Boyd's particular brand of charm.

Joe Cozens and Barbara Machin wrote it, Philippa Langdale directed, first shown in September 2005. Trevor Eve leads as Det Supt Peter Boyd, with Sue Johnston as Dr Grace Foley, Wil Johnson as DI Spencer Jordan, Esther Hall as Dr Felix Gibson, Georgia Mackenzie as DS Andy Stephenson and Claire Goose as DS Amelia Silver. Nina Wadia plays Roshni Mehta, Gerard Murphy James Alcock, Sara Stewart Claire Yardley, and a young David Walliams turns up as Bell.

A mummy in a plane wreck could have been a gimmick. Here it works because the episode treats it as evidence rather than spectacle, and lets the horror come from what was done to both bodies while they were alive. Part two owes us answers.