Theo Mayve is a love atheist. He’ll watch movies for the motorcycles and leather jackets but turn them off the second he gets a whiff of romance. To prove love doesn't exist, he’s broken ninety-nine hearts without falling for a single one. If he breaks one more before his brother’s upcoming wedding, he’ll win their bet to inherit the love of his life, Molly, his gramps’s vintage Mustang, and he’ll prove once and for all love is just an illusion.

To sweeten things, Astrid Lundgren, his childhood crush, former best friend, and sworn enemy—the only girl who's managed to come anywhere close to his heart—wanders back into his life when she sets foot in his auto shop. She’s brokenhearted and hoping to rekindle an old friendship. Theo, however, determines to make her Girl #100 and seek revenge for the past. As he begins to realize, breaking Astrid’s heart might not be as easy as he thought, especially when he starts to find his. A conversion of faith seems possible as his love atheism begins to wilt and time and his family work against him.

If he falls for the girl, he’ll have to recant years of professed beliefs, but if he chooses the car, he’ll lose his last shot at love. The mustang or the girl. Pride or defeat. Loneliness or love. Whatever he decides could ruin his life, for better or for worse.