Robin is shocked but thrilled when Hannah arrives on his doorstep with a two year old and a suitcase and announces that Freddie is his son. Her husband Marcus was less happy to learn that Hannah had a fling just before their wedding, but now he's longing to spend some time with the little boy he thought was his, so he takes on a house-sit a few streets away. Jo, over the road, is intrigued by the attractive newcomer, and quickly finds an excuse to learn more, but Hannah, always wanting what she can't have, is also wondering whether Marcus is the one, after all...