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….

When Aethelthryth—“Ethel” to her modern-day Manhattan neighbors—finds her sworn nemesis Lazlo Enyedi with no memory of who or what they are, an ancient hunt becomes an unexpected chance at forbidden passion. He’s crashing on her couch, solving her sudoku puzzles, and looking at her like she’s his eternal flame (minus the whole bursting-into-ashes part). As his memories slowly return, Ethel realizes she might be in danger of losing more than just her head…

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.

Rue Siebert might not have it all, but she has enough: a few friends she can always count on, the financial stability she yearned for as a kid, and a successful career as a biotech engineer at Kline, one of the most promising start-ups in the field of food science. Her world is stable, pleasant, and hard-fought. Until a hostile takeover and its offensively attractive front man threatens to bring it all crumbling down.

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.

Cat should be afraid of Brigan—the devastatingly gorgeous stranger at a Halloween party whose very presence makes everyone else fall at his feet. But while his supernatural allure drives others to mindless obsession, Cat somehow keeps her wits…even as she surrenders to temptation. When this cursed being realizes she alone can see his true nature, one night of searing passion could break a centuries-old spell—or doom them both.

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.

Shy, awkward Cade Monroe must be the only man in Florida who hates the beach. But when the most beautiful woman he’s ever seen kisses him unexpectedly one summer night, he might be forced to change his mind. A year later, and he’s still pining after her. The only catch? She doesn’t seem to remember the kiss. In fact, Cade isn’t sure she even knows he exists. Nora Whitfield has definitely noticed Cade, the dark-haired, hot-in-a-scowly-way guy who gets coffee from her every morning. But with a past full of heartbreak, Nora isn’t looking to get involved.

Mackenzie Carter has had some very bad dates lately. Model train experts, mansplainers, guys weirdly obsessed with her tail—she hasn’t had a successful date in months. Only a year out of residency, her grandmother’s obsession with Mackenzie finding the perfect mate to settle down with threatens to drive Mackenzie barking mad. Out of options, it feels like a small thing to tell her grandmother that she’s met someone. That is, until she blurts out the name of the first man she sees and the last man she would ever date: Noah Taylor, the big bad wolf of Denver General.

It’s Valentine’s Day weekend, and Charlotte and Seth are not looking for romance. Armed with emotional-support bear spray, Charlotte is in self-imposed isolation and on guard from men. Having a stalker can do that to a person’s nerves. Just across the hall and giving off woodsy vibes is Seth, a recently divorced arborist. As in today recently. Heights, he’s fine with. Trust? Not so much.

Callum Flannelly would rather dive into an open grave than take a stranger to dinner. But he can only inherit the family undertaking business under one condition: He must marry before his 35th birthday. So it’s out of the mortuary and into the dating scene. Lark Thompson came to Galway, Ireland to embrace life, not be reminded of losing her husband by moving in next to a funeral home. Then, the vivacious Texan animator learns of painfully shy Callum’s dilemma and makes it her mission to help him find The One.

High school sweethearts Sarah and Caleb Linwood have always been a sure thing. For the past seventeen years, they have had each other’s backs through all of life’s ups and downs. But Sarah has begun to wonder . . . who is she without her other half? When she decides to take on a project of her own, a fundraising gala in memory of her late mother, Sarah wants nothing more than to prove to herself—and to everyone else—that she doesn’t need Caleb’s help to succeed. She’s still her mother’s daughter after all, independent and capable.

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...

One typo, and a boy and girl connect by chance. Wishing each other a happy Valentine’s Day isn’t the end. In fact, it becomes a friendly annual tradition—with rules: no pics, no real names, nothing too personal. As years pass, the rules for their email “dates” are breaking, and they’re sharing more than they imagined—including the urge to ask…what if we actually met?