Housewife Molly Pargeter arranges for her family to travel to a Tuscany summer rental, where she meets a variety of eccentric locals but is most fascinated by Chrissie and Buck Kettering, who own the villa.
La Felicita is hit by a water shortage, forcing the Pargeters to shack up with the Ketterings.
Molly pieces together the clues connecting Buck, Nancy and the local waterboard but her snooping draws threats from the displeased ex-pats. Meanwhile, Haverford tests his chances with his forgetful ex-flame.
As holiday's end draws nearer, Molly realises that the answer to her mystery is at the end of the Piero Della Francesca Trail. As she sets off on her trip of discovery, Haverford's night of passion ends in farce.