Strangely unsatisfying ending, but also satisfying as it was the only ending that could work and make sense. So Lindsay Denton was, to an extent, unwillingly and unwittingly involved in the conspiracy to kill Tommy, the super witness. She knew, when she was in the car, that Tommy would be killed – but not how and where and when, and so she was not the master criminal mastermind she hinted at sometimes, but she wasn’t a goody-two-shoes either. And of course, Dot Cottan, the caddy, was still corrupt and pulling most of the strings (along with Jane Akers) in order to kill off Tommy as he had too much incriminating evidence against bent coppers. And Dryden was only guilty of underage ‘sex’ and perverting the course of justice by taking his wife’s speeding ticket, but not involved in the main conspiracy to kill policemen.
In the end, it all came back to Carly Kirk. Who was being pimped out by ‘Tommy’ (and Prashad) to blackmail policemen. Lindsay Denton, following Dryden, saw Tommy beating up Carly and tried to follow it up. Unfortunately for her, that meant that she tried to arrest Tommy (on the sly because she didn’t want to tell her colleagues how she knew about Carly Kirk) but was confronted by Jane Akers, his witness protection officer. She then later came to Lindsay and drew her into a conspiracy to kill Tommy – giving her a shedload of cash to bind her in. Lindsay didn’t know the details, or who else was involved, or that a tracker was actually placed on her car to facilitate the ambush.
And so Steve Arnott, who at the beginning of the episode appeared to be smitten with Lindsay, was going ‘undercover’ and worked out that the cash was with Lindsay’s mother’s things and that she had been using someone else’s computer. The cash was incriminating and she was convicted for conspiracy to murder and life imprisonment – when really she probably didn’t deserve such a harsh sentence. And Dot Cottan is now a permanent member of AC12 – profiting while everyone else fails.