Tonight's finale may or may not have provided an answer to that mystery, as Brannick confessed to committing murders in the 90s, but only because the 'real' Goliath threatened to kill his wife if he didn't. In the end, Brannick managed to wriggle his way out of the entire situation after killing Pat Keenan and passing him off as Goliath. While we can assume that Brannick is fibbing, it still wasn't made entirely clear if he's the mastermind assassin behind it all, or if he really was being forced to commit his crimes by another indvidual. But if it feels like there are a lot of unanswered questions, there's a pretty good reason for that. As the continuity announcer revealed at the end of the episode, the Northern Ireland-set drama will indeed be back for a second series.