The swimming pool

It's summer, and for teachers Ed and Natalie Steele this means six weeks off work with their young daughter Molly.

Their lives are predictable and uncomplicated - or, at least, they were - until they met the Channings.

Suddenly, glamorous Lara Channing, a former actress leading an eccentrically lavish lifestyle, is taking Natalie under her wing and the stability of summer takes an exciting turn.

But are there hidden motives behind this new friendship? And when the end-of-summer party at the lido is cut short by a blackout, Natalie realises that she's been kept in the dark all along.