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.

Like an avenging, purple-haired Jedi bringing balance to the mansplained universe, Bee Königswasser lives by a simple code: What would Marie Curie do? If NASA offered her the lead on a neuroengineering project—a literal dream come true after years scraping by on the crumbs of academia—Marie would accept without hesitation. Duh. But the mother of modern physics never had to co-lead with Levi Ward.

The many lives of theoretical physicist Elsie Hannaway have finally caught up with her. By day, she’s an adjunct professor, toiling away at grading labs and teaching thermodynamics in the hopes of landing tenure. By other day, Elsie makes up for her non-existent paycheck by offering her services as a fake girlfriend, tapping into her expertly honed people-pleasing skills to embody whichever version of herself the client needs. Honestly, it’s a pretty sweet gig—until her carefully constructed Elsie-verse comes crashing down.

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.

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.

Mallory Greenleaf is done with chess. Every move counts nowadays; after the sport led to the destruction of her family four years earlier, Mallory’s focus is on her mom, her sisters, and the dead-end job that keeps the lights on. That is, until she begrudgingly agrees to play in one last charity tournament and inadvertently wipes the board with notorious “Kingkiller” Nolan Sawyer: current world champion and reigning Bad Boy of chess.

Bad luck has always followed Olivia Marshall...or maybe she's just the screw-up her family thinks she is. But when a "What are you wearing?" text from a random wrong number turns into the hottest, most entertaining - albeit anonymous - relationship of her life, she thinks things might be on the upswing.

Stella Lane thinks math is the only thing that unites the universe. She comes up with algorithms to predict customer purchases - job that has given her more money than she knows what to do with as well as way less experience in the dating department than the average 30-year-old. It doesn't help that she has Asperger's and that French kissing reminds her of a shark getting its teeth cleaned by pilot fish. She decides that she needs lots of practice - with a professional - which is why she hires escort Michael Phan.

Misery Lark, the only daughter of the most powerful Vampyre councilman of the Southwest, is an outcast—again. Her days of living in anonymity among the Humans are over: she has been called upon to uphold a historic peacekeeping alliance between the Vampyres and their mortal enemies, the Weres, and she sees little choice but to surrender herself in the exchange—again...

For the first time in her life, Clementine “Emmy” Ryder has no idea what she’s doing. She’s accomplished everything on her to-do list. She left her small hometown of Meadowlark, Wyoming; went to college; and made a career for herself by doing her favorite thing: riding horses. But after an accident makes it impossible for her to get back into the saddle, she has no choice but to return to the hometown she always wanted to escape.

Rosie Graham has a problem. A few, actually. She just quit her well-paid job to focus on her secret career as a romance writer. She hasn’t told her family and now has terrible writer’s block. Then, the ceiling of her New York apartment literally crumbles on her. Luckily she has her best friend Lina’s spare key while she’s out of town. But Rosie doesn’t know that Lina has already lent her apartment to her cousin Lucas, who Rosie has been stalking—for lack of a better word—on Instagram for the last few months.

Hallie Piper is turning over a new leaf. After belly-crawling out of a hotel room (hello, rock bottom), she decides it’s time to become a full-on adult. She gets a new apartment, a new haircut, and a new wardrobe, but when she logs onto the dating app that she has determined will find her new love, she sees none other than Jack, the guy whose room she snuck out of.

Hi, my name is Bree Camden, and I’m hopelessly in love with my best friend and star quarterback Nathan Donelson (so is half of America, judging by the tabloids and how much the guy dates). The first step is admitting it, right? Except, I can never admit it to him because he clearly doesn’t see me that way, and the last thing I want is for things to get weird between us. Nothing but good old-fashioned no-touching-the-sexiest-man-alive platonic friendship for us! Everything is exactly how I like it! Yes. Good. (I’m not crying; I’m just peeling an onion.)

Gigi Graham has exactly three goals: qualify for the women's national hockey team, win Olympic gold, and step out of her famous father's shadow. So far, so good, except for two little things. Fine—a little thing and a big, grumpy thing. She needs to improve her game behind the net, and she needs help from Luke Ryder. Ryder is six-foot five, built, opinionated, rude . . . and sexy as hell. But he's still the enemy.