THE SWITCH

A sexual game goes dangerously wrong for two couples in this domestic thriller.

Elena and Adam feel lucky when they move to Wimbledon Village to housesit for Adam’s aunt. Their old flat in London was tiny, their neighbors loud. Now they marvel over the shops and pubs and adore their peaceful nights. That peace is doomed, however, when Elena meets Sophia at a local coffee shop and strikes up a friendship with her. Sophia and her husband, Finn, are glamorous and gorgeous, with a casual way around money that impresses Elena, who didn’t grow up in a wealthy home. But their friendship takes a dark turn when Sophia suggests she and Elena swap husbands for a night without telling Adam and Finn. Relying on blackout curtains, uncharged cell phones, and strategically unscrewed light bulbs, Sophia says, they can have naughty fun and their partners will never know. This plan does not seem likely to succeed in any way in real life, of course. Elena is reluctant at first, but as her relationship with Adam begins to fray and she finds herself attracted to Finn, the swap seems more appealing. But what starts out as a playful romp could have far-reaching consequences. Sophia has an ulterior motive, one that any reader will figure out quickly. Samson does venture a little beyond the obvious, touching on how class distinctions and unrealistic expectations take a toll on a marriage. She makes a token nod to the joke that men are so inattentive they wouldn’t notice such a swap and so amorous they wouldn’t mind if they did. But she never builds on that irony, and her novel grows more improbable as the story draws to its oddly unsatisfying conclusion.

A hard-to-believe setup and unsatisfying conclusion mar this thriller.