Octavia Brennan is a beautiful yet flawed young woman, living the high life in 1970s London. Though she is deeply flirtatious and has, by her own admission, slept with many men, she has never found happiness with any of them.
After bumping into an old school friend, Gussie, and falling for her fiancé, Jeremy, Octavia is invited to spend the weekend with them on their canal boat. Characteristically, she convinces herself that Jeremy cannot possibly have real affection for the overweight and clumsy Gussie, and she is determined to win Jeremy by the end of the weekend. But when Jeremy invites Welsh firebrand Gareth Llewllyn along for the ride, Octavia finds her plans disrupted in more ways than one.

• from wikipedia