The death of a diplomatic courier draws Detective Sergeant Hana Li to the US Embassy in London, while, en route on her own flight, MI5’s Madeline Delaney receives a warning of a bomb aboard.

While Hana and Brody pursue the killer, the embassy is placed under lockdown. Yet, Fox continues to stay ahead of their efforts. Simultaneously, a bomb is discovered aboard Delaney’s aircraft.

The death of a second guest at the embassy revealed a chilling connection: both victims had served on the same panel that had attributed the D-300 crash to Russia.

A single clue surfaces, altering the course of events for Hana. Meanwhile, aboard the aircraft, Delaney and Peterson race against time to disarm the bomb. Elsewhere, Banks and Jess painstakingly piece together crucial evidence.

Hana and Brody devised a snare to capture Fox, while Jess sought unexpected medical assistance to save Ruth. The mastermind behind the intricate plot was, at long last, brought to light.

As Hana and Brody confront their inner struggles, a deeper truth about the conspiracy unfolds, and together with Delaney, they strive to bring about justice.