Mara, Sadie, and Hannah are friends first, scientists always. Though their fields of study might take them to different corners of the world, they can all agree on this universal truth: When it comes to love and science, opposites attract and rivals make you burn….

Viola Bowen has the chance of a lifetime: to design a video game based on her all-time favorite book series. The only problem? Her co-lead is Jesse F-ing Andrews, a.k.a. her arch-nemesis. Jesse has made it abundantly clear over the years that he wants nothing to do with her–and Viola has no idea why. When their bosses insist a wintery retreat is the perfect team-building exercise, Viola can’t think of anything worse. Being freezing cold in a remote mountain lodge knowing Jesse is right next door? No, thank you.

All newly minted pediatrician Jamie Malek wants is to borrow a roasting pan for Christmas dinner. Unfortunately, that requires her to interact with Marc—her best friend’s troublemaking brother, who’s now a tech billionaire. He’s the one who got away. She’s the one who broke his heart. Outside, a howling blizzard. Inside, a crackling fire. Suddenly, being snowbound with the man she never expected to see again might not be such a bad way to spend a winter’s night.

As a third-year PhD candidate, Olive Smith doesn't believe in lasting romantic relationships—but her best friend does, and that's what got her into this situation. Convincing Anh that Olive is dating and well on her way to a happily ever after was always going to take more than hand-wavy Jedi mind tricks: Scientists require proof. So, like any self-respecting biologist, Olive panics and kisses the first man she sees.

Evie Crowe is starting over in a strange town with her newborn, and men are the furthest thing from her mind. If only the quiet, hulking farmer, Luke Ward, would stop coming into the thrift shop and piquing her reluctant interest. Evie wants to stay single all the way—she can’t trust anything more than friends-with-holiday-benefits. But Luke is in it for the long haul. He’s fixed on making this a Christmas Evie will remember forever. If she gives him a chance.