When brought face-to-face with the past, ignoring what the heart wants in favor of what the head says is never easy…

Lacie Cunningham, a graduate student pursuing a doctorate in math, has a romantic past that proves falling in love isn’t worth the trouble. Better to use the mathematical optimal stopping theory to find her ideal companion. Currently, she rejects all dating “situationships” before things get too emotional. Eventually, when she makes it through thirty-seven percent of her dating window, she’ll stop and the next guy she meets who is better than everyone she’s dated before should be The One.

But at a music festival, when she happens on her great high school heartbreak, musician Justin Van Meer, her carefully laid plans of “math-making” begin to fall apart. The problem is, despite the gut-wrenching history between them, the more time she’s forced to spend time with him the more she realizes she’ll never meet anyone more charming, more exciting, more wonderful to be with than it was to be with him.

Told in a dual timeline between past and present, Lacie must decide what’s more important—sensible reliance on a statistical strategy or a passionate fight for true love.