Nearly 40 years ago aliens crash-landed in the UK. They look like us, but are forced to live in a ghetto. Border control officer Lewis falls in love with one.
Vivienne Acheampong / Josef Altin / Alex Beckett / Michaela Coel / Chanel Cresswell / Tom Davis / Holli Dempsey / Daniel Eghan / Neil Fitzmaurice / Trystan Gravelle / Jim Howick / Reuben Johnson / Samson Kayo / Ed Kear / Chetna Pandya / Shaun Parkes / Michael Socha / Roy Thorn / Ashley Walters / Bronson Webb
With many of Troy's inhabitants trying to flee the gang war the authorities impose a lock-down - no-one in, no-one out. Lewis realises he has to bring the conflict to an end but to do so he will have to make a sacrifice.
After he accidentally prevents a hit on the human side of the wall, Dominic is tasked with taking out small-time drug dealer Sean. The conflict between Antoine and Fabian escalates into all-out gang warfare.
Lilyhot tries to persuade Antoine to take control of Troy back from Fabien, but Antoine just wants a quiet life now and sees through her motives. Meanwhile, Lewis reluctantly agrees to smuggle "Fur" through the checkpoint.
Lilyhot tells Lewis that his alien father, Antoine, is in prison and that she has a plan to get him out but needs his help. Border guard Truss begins to suspect that Lewis is involved in some dodgy business.
Lewis - a border guard manning the checkpoint of the alien ghetto known as Troy, has his life thrown into chaos after a chance meeting with Lilyhot - the webcam girl he has been lusting after.