Nicci Gerrard: The Moment You Were Gone (UK 2007)

From the Publisher:
Gaby and Nancy were inseparable when they were young. They had no secrets and believed nothing would break up their friendship, even when each found love -- Gaby with Connor and Nancy with Gaby's brother, Stefan.

Then one day Nancy left Stefan and walked out of all their lives. Gaby has not seen her now for nearly twenty years, and in all that time she has never known where Nancy went or why.

Now long married to Connor, Gaby is preparing to take their only son Ethan to university for his first term when, quite by chance, she spots Nancy on a television report about a flood in a tiny village in Cornwall. And in a recklessly impulsive moment, she turns up on Nancy's doorstep, unannounced.

Nancy's secret explodes into all their lives, wreaking havoc on long-held assumptions and beliefs, and Gaby is forced to examine her own past in order to try to save what is most precious to her.

Nicci Gerrard: The Moment You Were Gone. Penguin, ISBN: 0141024062 (August, 2007), 468 p., £6.99.