The first hour was a classic, excellent cop throws it all away episode. Agnew, despondent over Katia's death - that is, murder by Geddes - gives away his money, almost takes his life, has some kind of heart-attack-like episode, and confesses it all to his former partner Sean, now a druggie staying at Agnew's place. Agnew veers from confessing it all to the world to planning an escape to Germany, but can't quite do either. He walks in to the Detroit Police building - only to discover along with the audience the huge surprise of the evening: Sean has confessed to the McCann and related murders. And, since Agnew earlier confessed to Sean, Sean is in possession of details that only the killer would know. Brilliant!
Of course, this won't satisfy Internal Affairs Boyd, who's pieced the real truth together, and the second hour features a great pivot by Agnew, who's regained his sense of self-preservation, and now is thinking fast about how he can walk away from this without a murder charge against him. He does feel bad about Sean going down for this, but not bad enough to really stop Sean, and in the end Agnew throws in a phone which offers physical evidence in support of Sean's confession.
But the factor that tips the balance against Boyd as the higher-ups meet to sort this out is that Katia is nowhere to be found, depriving Boyd of the one witness who would push his story into the believable column even with Sean's confession working against that. And so, in one of the crowning ironies of the series, Geddes' dispatching of Katia last week saves the day for not only Geddes but Agnew tonight.
But there's one last pulsing question mark left hanging in this story: Agnew goes to claim Katia's body. The coroner or whoever asks Agnew for Katia's name. Agnew hesitates and there the story ends (I hope, for just now). If he says Katia, that will give evidence which Boyd at some point could dig up and use against Agnew. If he says another name, that would in effect be disrespecting the woman he loved.
I'm betting AMC will give us a chance to see what he does next year.
See also Low Winter Sun 1.1-2: High Hopes ... Low Winter Sun 1.3: Katia and the Bridge ... Low Winter Sun Penultimate Review