Billy Wallace returns to London to seek revenge. Meanwhile, someone is picking off more of Koba's associates.

Marian Wallace is forced out of hiding and made to confront his past as Koba launches a terrifying helicopter attack on his enemies

As Luan faces a desperate race against time, Ed starts to question where his own loyalties lie, and events reach an explosive climax.

The pieces fall into place for Elliot as he tries to free himself of the Investors once and for all, but manoeuvres elsewhere threaten to derail him.