Episode 5

The hunt for H intensifies, and Steve and Kate start to wonder whether Hastings is guarding a dark secret. It is the kind of thought that would once have been unthinkable inside AC-12. But the fact that they are thinking it tells you everything about the state of the unit. The investigation is no longer just about the OCG; it is about the man in the office at the top. The unit has turned on itself before, but never on the man who built it.

The episode is a slow tightening of the screw. The partnership between Arnott and Fleming is tested as they work out how to investigate their own boss without destroying the team in the process. The wider cast moves through the fallout, with Sindwhani and Biggaloe adding to the pressure and the OCG figures staying dangerous in the background. But every conversation is a negotiation, and every loyalty is up for examination. The suspicion is doing its work quietly, which is how suspicion works best. The episode is patient with the small moments, and the small moments are where the damage shows.

Jed Mercurio wrote it, Susan Tully directed. Adrian Dunbar gives Hastings the performance of a man with something to hide, and Martin Compston's Arnott and Vicky McClure's Fleming do the difficult work of suspecting him. Rochenda Sandall's McQueen, Tomi May's Minkowicz, Gregory Piper's Pilkington, Taj Atwal's Sohota, Elizabeth Rider's Wise, Ace Bhatti's Sindwhani and Polly Walker's Biggaloe complete the cast. It is an ensemble the show trusts completely, and the trust shows on screen.

The episode is about how institutional loyalty gives way under duress, and the show tracks that process with real patience. The question of Hastings is not answered here, which is the right call. A secret that big needs room to breathe. The episode gives it that room, and the tension keeps building. The question is not whether Hastings has a secret; it is what the secret is worth to the people who find it. And the answer, when it comes, will test everyone's idea of the man.