Towers of Silence (2)

Part two pulls the threads tight, and they lead somewhere you wouldn't have guessed from a mummy in a desert. The mutilation murders of two Indian men, a fresh prison suicide, the strange business of Zorarosterism and that seven-year-old armed robbery at Heathrow all turn out to feed one machine: counterfeit drugs, and an international pharmaceutical cartel happy to kill to protect its trade.

The episode's best material belongs to Spence. DI Spencer Jordan goes undercover as an inmate to work on the man convicted of the murders, trying to find out why they really happened and who actually ordered them. It fails, in the cruellest way. The prisoner is too frightened to say anything at all, and he kills himself before Spence can crack him. Wil Johnson plays those scenes with real weariness; you watch a good copper realise he's been outmanoeuvred by fear itself. The cartel doesn't need violence in that cell. Silence does the job for it.

Then they get bold. The cartel attempts to recruit Boyd as a covert operative inside their operation, which is either flattering or suicidal depending on how you read it, and the show milks the ambiguity nicely. Trevor Eve gets to sit across from people who genuinely believe they own him, and disagree.

Joe Cozens and Barbara Machin wrote it, Philippa Langdale directed, shown the night after part one in September 2005. Trevor Eve leads as Det Supt Peter Boyd, with Sue Johnston as Dr Grace Foley, Esther Hall as Dr Felix Gibson and Georgia Mackenzie as DS Andy Stephenson. Paul Bhattacharjee does double duty as DCI Chowdray and Mr Irani, with Nina Wadia as Roshni Mehta, Sara Stewart as Claire Yardley, Henry Ian Cusick as Jeremy Allen and David Walliams as Bell.

It's a dense hour and it earns its sprawl. Airport robbery to fake medicine is a long walk, but greed makes short work of distance, and this lot were greedy all the way down.