It's an evening like any other when an explosion rips through the leafy Oxford suburb Sarah Tucker calls home.

It's an evening like any other when an explosion rips through the leafy Oxford suburb Sarah Tucker calls home.

In the aftermath, a house now stands devastated, with two adults dead and a young girl missing.

With the police more interested in keeping the neighbours from rubbernecking than in searching for the missing child, Sarah becomes obsessed with finding her.

She enlists the help of Zoë Boehm's investigation agency, but Sarah's and Zoë's search reveals more secrets than answers, taking them from Oxford's cobbled streets to the rugged outer reaches of the British Isles. As Zoë and Sarah draw closer to the truth, they are caught in a web of conspiracy and come up against government forces, cold-blooded mercenaries and vengeful loners.