A psychological thriller from the author of the #1 bestseller The Passenger and Til Death Do Us Part.

Lucy is a successful businesswoman who loves nothing more than to spend her time competing in fun challenges with friends, colleagues, and even strangers. But she might just have met her match when she encounters Jess, a woman who is not used to losing at anything.

Jess is very much like Lucy when it comes to a fondness for competition, only a more extreme version, and as the pair become friends, it's clear that a rivalry is developing between them in the fields of business, love and beyond.

But as the lives of both women become more intertwined, that rivalry becomes more intense, and by the time it reaches the point of their friendship breaking down, it seems that there is nothing either woman won't do to come out on top.