Line of Duty spoilers follow – including season 6, episode 3 and its ending. An AC-12 reunion. One police officer dramatically killed in the line of duty. And another taken, tail between legs, to be questioned by anti-corruption. This week's (April 4) Line of Duty was a jam-packed one. So let's take a moment to break it down. Has it been Buckells all along? BBC So we finally have an answer about the elusive Detective Superintendent Ian Buckells. Or do we? Fans have long held suspicions that Buckells could be, as Hastings would put it, a "bent copper". Thanks to his tendency to be in the wrong place at the wrong time (or the right place at the right time?) and his deep disdain for AC-12, he's been one to keep a close eye on ever since the first season.