Solidarity (1)

A skeleton under Westminster is never just a skeleton. Workmen digging in a sewer found the remains of Piers Kennedy, Falklands hero turned peace campaigner, missing since 1983, the year he made his anti-nuclear speeches. He went from national symbol to national embarrassment in the space of a few years, and someone put him in the city's drains. The case reeks of official fingerprints from the start.

Grace Foley knew him, which puts her on awkward ground. She is still on a Government watch list for her own anti-war views, and the past she shares with Kennedy is a personal one. His old circle surfaces with grudges intact: Lucy Christie, the girlfriend he left for a fling with Bonnie Yorke, now with fellow campaigner Ralph Palmer; Murray, the marine with charm and a short fuse; and Oleg Leontyev, the Russian friend who turned on Kennedy after the KGB killed his parents. Lucy's father, now Lord Christie, has dog hairs on the corpse to explain. The pool of suspects is deeper than the sewer.

Grace tracks down Murray, who has been chewed up by post-traumatic stress, and he hands her a tape that allegedly shows Ministry of Defence police killing Piers. The same police force is watching the case like hawks. Eve goes back to the sewer and finds herself and Boyd under arrest by the very people they are investigating, and Defence Minister Jane Hussey tells Boyd in plain terms to stop. But he will not.

Barbara Machin and Ed Whitmore wrote it, with Andy Hay directing. Trevor Eve's Boyd, Sue Johnston's Grace, Tara Fitzgerald's Eve, Wil Johnson's Jordan and Eva Birthistle's Cavendish are joined by Jonathan Bryan as Hugo Christie, Cara Horgan as young Lucy, James McGregor as young Oleg, Adam Rayner as Kennedy and Frances Tomelty as Hussey.

It is the kind of episode that reminds you why the series was never cosy. The skeleton is just the start of it. The rot the team are digging up runs through the institutions above the ground.