Nick (David Tennant) is happily married: his wife and children are everything to him, but when his first love appears out of the blue he suddenly starts to question everything. Can they go back to what they had all those years ago?

There’s nothing really wrong with Paul’s (Ashley Walters) life – he’s got a lovely wife, a baby boy, a nice house… it’s just a bit ordinary, a bit lacking in excitement. Then he catches sight of a girl on his way to work and feels an instant attraction – could this really be love at first sight? He can’t stop himself from finding out…

Holly (Billie Piper) is a young unfulfilled teacher who is in an unsatisfactory relationship with a married man. She suddenly finds herself drawn to one of her female pupils, who appears to feel the same way.

When Sandra’s (Jane Horrocks) youngest child leaves home she realises that her marriage has become stale: she and her husband have little to say to one another, and besides this, he’s having an affair. Then she meets someone who somehow makes her feel alive again – has she really found her soulmate, and how will her husband feel now that the shoe is on the other foot?

Adrian (David Morrissey) is a divorcee who has been searching for true love. It's not been easy but he's not giving up. Still a romantic, he believes in it whole-heartedly, despite his failed marriage. Just when he thinks he might have found it, he finds that he is the victim of another obsessive love that threatens to scupper his future.