Harbinger (2)

The second half of Harbinger narrows everything down to one woman, and the result is properly chilling. Boyd holds to his belief that Donald Rees was no killer, and the team are left to pick through the loose threads. They lead somewhere nobody wanted to go. Grace Foley comes to believe that Julie, the Geigers' babysitter when their son Andrew died, killed the boy deliberately and exposed her own daughter to radiation, all to feed a psychological hunger for attention. Sue Johnston delivers that theory with the flat certainty of someone who has seen this before.

Una Mason, the nurse on duty when Andrew died, had her doubts at the time and shared them with her boyfriend Glenn Burke. That conversation set the whole tragedy moving. Burke put the Geigers up to haunting the Rees family and blackmailing Donald for money, then murdered the old couple when they tried to give it back. He torched their house to burn the evidence, and Una only survived because she had already got out. Then Julie breaks into her own home and kills Burke when he comes after her.

But the case does not close cleanly. If Julie's illness was another performance, did she kill Donald when he found out what she had done? The episode declines to answer, and that refusal is the most unsettling thing about it.

Barbara Machin and Ed Whitmore wrote it, with Marc Jobst 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 Cecilia Noble's Una Mason, Graham Turner's Burke, Ian Hanmore and Amelda Brown as the Geigers and Charles Edwards as Donald Rees.

The black coats turned out to be a distraction. The horror was closer to home all along, sitting in a hospital bed and looking pitiful. If Julie was performing, she played the whole world, Boyd included, and that is the kind of ending this series does best.