California, 1993: Neil Collins and Adam Tayler, two young British men on the cusp of adulthood, meet at a hostel in San Diego. They strike up a friendship that, while platonic, feels as intoxicating as a romance; they travel up the coast together, harmlessly competitive, innocently collusive, wrapped up in each other. On a camping trip to Yosemite they lead each other to behave in ways that, years later, they will desperately regret. The story of a friendship built on a shared guilt and a secret betrayal, 'The Faithful Couple' follows Neil and Adam across two decades, through girlfriends and wives, success and failure, children and bereavements, as power and remorse ebb between them.