A week after the alien ships arrival over Bristol, the group struggle with what to do next. Steven still hasn't made it to the farmhouse, and something is calling Dan back toward the city

The fate of Steven and Katie is revealed, and we meet the mysterious Isaac. A broken man for whom the arrival of the ship changed everything.

The group return to the farm, only to find they have been visited by a mysterious stranger who comes bearing a warning of things to come.

The government interrogate a prisoner who may have information about the UFO. However, matters are complicated when potentially hostile forces arrive to take over.

A flashback to Bristol of the past reveals how a chance discovery almost 200 years prior may have led to the arrival of the UFO in present day.

The group are forced to break into a historic Bristol building in order to prevent the impending attack. However, it may still be under guard and government forces are in pursuit.

Nicole is forced to put her brief training into action when a stranger arrives at the farmhouse. Meanwhile, Brennan and Cole plan retaliation against a covert government team.

Nicole fights for her life as the government attempt to track down the rest of her group. She receives help from an unlikely ally.

In a last ditch attempt to prevent the invasion, the group venture into the tunnels beneath the city. However, they may not be the only ones down there.

The group have a tough decision to make when it becomes clear the only way to prevent disaster is to make a significant sacrifice, and the clock is ticking.