On the surface, Lydia Fitzsimons has the perfect life—wife of a respected, successful judge, mother to a beloved son, mistress of a beautiful house in Dublin. That beautiful house, however, holds a secret. And when Lydia’s son, Laurence, discovers its secret, wheels are set in motion that lead to an increasingly claustrophobic and devastatingly dark climax.From the international bestselling author of Unraveling Oliver, an “unputdownable psychological thriller with an ending that lingers long after turning the final page” (The Irish Times) about a Dublin family whose dark secrets and twisted relationships are suddenly revealed.

    Yet, even as he matches wits with his seemingly clairvoyant opponent, Gurney’s tragedy-marred past rises up to haunt him, his marriage approaches a dangerous precipice, and finally, a dark, cold fear builds that he’s met an adversary who can’t be stopped.In the end, fighting to keep his bearings amid a whirlwind of menace and destruction, Gurney sees the truth of what he’s become – what we all become when guilty memories fester – and how his wife Madeleine’s clear-eyed advice may be the only answer that makes sense.A work that defies easy labels -- at once a propulsive masterpiece of suspense and an absorbing immersion in the lives of characters so real we seem to hear their heartbeats – Think of a Number is a novel you’ll not soon forget.