Double Bind (2)

Forty years inside for killing your own parents, and then the man simply walks off. That is the hook of Double Bind (2): Daniel Lennon, a mental patient who has spent four decades locked up for the brutal murder of his mother and father, slips away from custody, and the cold case team finds itself with fresh leads on a very old crime.

What starts as a missing-patient file soon turns into something stranger. Boyd digs into the circumstances of Lennon's instability and finds the picture refuses to stay simple. The suggestion is that alternative practices may have had a hand in his fragile state over the years, which pushes the investigation away from tidy questions of motive and towards something murkier: how a mind gets shaped, or unshaped, by forces nobody was keeping an eye on. It is a good fit for the show, honestly. Waking the Dead has always been happiest when the forensics run out and the psychology takes over, and here the two are tangled together from the start.

Barbara Machin and Richard Warlow wrote it, Andy Hay directed. Trevor Eve's Boyd does what Boyd does, which is worry at a case like a dog with a bone while everyone around him suggests, reasonably, that he get some sleep. Sue Johnston is back as Dr Grace Foley, Tara Fitzgerald as Dr Eve Lockhart, Wil Johnson as DI Spencer Jordan and Félicité Du Jeu as DC Stella Goodman. The Lennon family circle is filled in by Miles Anderson as Daniel, Jill Baker as Dr Caroline Ritter, Hugh Mitchell as Mark, Greg Hicks as Chris and Joanna Hole as Gloria.

As the second half of a two-parter it carries the usual burden: it has to pay off what part one set up while opening new questions at the same time, and it mostly manages the juggle. The pleasure of the episode is watching routine police work grind up against damage this old and this private. A murder from forty years ago leaves almost nothing to test and plenty to argue about, and the team argues beautifully.

Whether Lennon did it, or merely took the blame, is the question the hour keeps circling. The show doesn't hand you the answer early, and it's better for that.