Kristin Billerbeck examines the science of happiness in her latest novel, The Theory of Happily Ever After. The summary says: "According to Dr Maggie Maguire, happiness is serious science, as serious as Maggie takes herself.
But science can't always account for life's anomalies - for instance, why her fiance dumped her for a silk-scarf acrobat and how the breakup sent Maggie spiraling into an extended ice cream-fueled chick flick binge.
Concerned that she might never pull herself out of this nosedive, Maggie's friends book her as a speaker on a "New Year, New You" cruise in the Gulf of Mexico. Maggie wonders if she's qualified to teach others about happiness when she can't muster up any for herself.
But when a handsome stranger on board insists that smart women can't ever be happy, Maggie sets out to prove him wrong. Along the way she may discover that happiness has far less to do with the head than with the heart." The Theory of Happily Ever After is out in May 2018.