Season two of The Fall felt like an ending. The Belfast Strangler (Paul Spector, played by Jamie Dornan) had been identified, shot and caught. Case solved, time for DSI Stella Gibson (Gillian Anderson) to pack up and head home. And this is where most TV series end.

Season 3 instantly picks up the action, concentrating on the aftermath of the manhunt: doctors working furiously to save Paul's life, the impact on his family and victims, the ensuing media frenzy, while the investigation ticks on. It's an aspect of police thrillers we rarely get to see. It's a feat Broadchurch tried and failed, but in this opening episode The Fall appears to be more focussed.

Writer Allan Cubitt created such intriguing characters in Spector and Gibson you want to know more. Most TV serial killers are paper-thin cyphers, evil incarnate operating to their own twisted code of conduct. There was a depth of characterisation that made Spector even more creepy. On the surface he had it all: incredibly good-looking, two kids and a happy family life, but underneath dark desires took control.

Stella Gibson is Gillian Anderson's best role since Dana Scully in The X-Files. By making Gibson a high ranking officer coming in from London to take charge, Cubitt added multiple layers touching on political tensions in Northern Ireland, the fear of violence in society, and in particular, sexist double standards. These are highlighted by having a strong female character taking charge and leading the investigation in her own way, criticised and scrutinised in a way her male colleagues never would be.

Series 2 of The Fall felt overlong and baggy in places. However, Cubitt has found more to explore; perhaps six episodes is stretching it too far, but Anderson's magnificent, controlled performance is worth tuning in for again and again.

The Fall Season 3 starts on BBC Two, Thu 29 Sep.