

6.247 minSeason 3 • Episode 4
LatestOperation Perseus reaches its climax as Kieran prepares to catch Shakiel with a car-load of automatic weapons. However, Spencer's killer, Jermaine King, has escaped from custody and kidnapped Ryan's sister, Tia.
A veteran beat cop and teenage girl fall to their deaths from a tower block in south-east London, leaving a five-year-old boy and rookie police officer Lizzie Griffiths on the roof, only for them to go missing. Detective Sergeant Sarah Collins is drafted in to investigate, working to find Lizzie before she comes to serious harm, but also to uncover the truth behind the grisly tower block deaths.
Acting
Gemma Whelan's controlled fury as the ice-cold Collins.
Writing
Harbinson's authentic canteen dialogue and procedural detail.
Production
Tower blocks as suffocing character — claustrophobic estate realism.
Creator
Patrick Harbinson
Trivia, insights & behind the scenes
Based on Kate London's novel 'Post Mortem' — she was a real Met detective, and it shows in the canteen politics.
The tower block setting deliberately echoes Grenfell-era conversations about social housing neglect and who gets left behind when systems fail.