Friendship is like a shark: it has to keep moving forwards to survive.

Esther and Laura have been best friends since they were seven. Quite a bit has changed since then . . . They've swapped school for full-time employment, boyfriends for bugaboos, experimental hair-dye for salon-preened locks - and their friendship has evolved just as much. But they remain close, knitted together by the bonds of time . . .

So when Esther is told that Laura has gone missing, she immediately leaves her husband and small child for San Francisco and begins to trace her friend's last movements. All she has is an email from Laura: 'I'm channelling Drew Barrymore, as ever. The Gospel, right?'

In trying to understand why Laura has disappeared, and what on earth Drew Barrymore has to do with it, Esther needs to look back. Back at the secrets woven into their friendship and the truths she's avoided facing for so long