Pete and Maddie find out that their 3 year old son, Theo, was swapped at birth with another boy. To their relief, Theo’s biological parents, Miles and Lucy, appear to want the same outcome as Pete and Maddie - to keep the boys they raised. Miles is initially friendly - he invites them on holiday, takes Pete surfing and keeps appearing at their door with new gifts for Theo. Is Miles "playing nice", or is he bulldozing his way into their lives? When Theo is thrown out of nursery, Lucy and Miles are quick to the rescue, offering up their lavish home and expensive nanny for Theo’s disposal. Pete wants to make things work with the couple and Maddie is keen to spend time with her biological son, David, so they accept the offer, unaware of just how wrong things can go… As the dynamic between the two sets of parents shifts, a fierce custody battle looms and cracks begin to appear in Maddie and Pete's relationship. Can they protect the boys they love, or will they lose everything?
