Kaye's world is shaken up when her sister Ruby returns with her boyfriend Michael. Eleswhere, as night falls, the Donahue family prepare nervously for the formidable race ahead.

The race is on and the road ahead is packed with dangers. The Donahues face up to a huge setback. Then, things go wrong on the Thames.

London's huge wall presents the racers with another massive obstacle. Meanwhile, The General and Faith hatch a sneaky plan and Jenny grows increasingly anxious.

Roman has a confession for Meg as he admits the real reason they joined the deadly street race. Kaye and Michael clash over whether to fight or flee.

There's trouble when the Volvo and the tow truck crash in the middle of nowhere. Lou and Ruby need spare parts. Fast. But they come at a steep price.

The ambulance, hot hatch and Volvo race into a deadly game of cat and mouse as they chase the prison truck into a clash with cops in Manchester's badlands.

The remaining racers near the finish line as they approach the Highlands, and Kaye reveals a secret she has been keeping for years when she makes a shocking confession to Michael.

An act of sabotage causes all hell to break loose. From the chaos, the final contenders emerge.