2018. It's Niall's wedding day as he follows his estranged 'brother' Ruben into a barn, away from all his guests. Here, in an explosion of violence, Ruben brutally and shockingly attacks him. Understanding why proves to be the driving question of this drama as we are catapulted back through the decades.

1989. Niall is struggling at university when he invites Ruben to join him and his flatmates for freshers week. What begins with excitement ends in devastating consequences.

1993. Niall is conflicted when asked by his mother to lie in court about Ruben's violence. Ruben seems to have changed for the better, so the decision weighs heavily on him.

2008. After a breakdown, Niall learns that Ruben has returned. Obsession takes hold, and a charged confrontation forces the brothers to face their fractured past.

2010. Niall and Ava face major life changes as Ruben struggles with his relationship. An impulsive choice between Mona and Niall has serious consequences for all involved.

2014. Niall has built a new life, but old ties resurface when Mona reconnects with Ruben. Events spiral toward an intense and devastating conclusion.