Lewis is a border guard at a checkpoint that patrols a wall, but after a chance encounter with mysterious alien Lilyhot his life is thrown into turmoil when he discovers that he's actually half alien.
After Lilyhot reveals to Lewis that his real alien father is in prison, Lewis agrees to help break him out.
Lilyhot wants to start a gang-war in Troy. Meanwhile, Lewis reluctantly agrees to smuggle drugs through the checkpoint.
With his suspicions of Lewis growing, Truss decides to follow him into Troy and soon discovers Lewis’ secret that he’s half alien. But when he is spotted in Troy by the Alien League, a movement that fights for alien equality, they gang together to hunt him down. It is down to Lewis to get Truss out of Troy before the Alien League find him…
Dominic is forced to become a hitman and finds himself tasked with murdering small-time drug-dealer Sean, while Lewis decides to hand himself in to the authorities.
Troy is put into lockdown, and with the help of Lilyhot, Lewis realises he has to bring the conflict to an end, but to do so a sacrifice must be made. Last in the series.