Two best friends. Ten summer trips. One last chance to fall in love. Poppy and Alex. Alex and Poppy. They have nothing in common. She’s a wild child; he wears khakis. She has insatiable wanderlust; he prefers to stay home with a book. And somehow, ever since a fateful car share home from college many years ago, they are the very best of friends. For most of the year they live far apart—she’s in New York City, and he’s in their small hometown—but every summer, for a decade, they have taken one glorious week of vacation together. Until two years ago, when they ruined everything. They haven’t spoken since. Poppy has everything she should want, but she’s stuck in a rut. When someone asks when she was last truly happy, she knows, without a doubt, it was on that ill-fated, final trip with Alex. And so, she decides to convince her best friend to take one more vacation together—lay everything on the table, make it all right. Miraculously, he agrees. Now she has a week to fix everything. If only she can get around the one big truth that has always stood quietly in the middle of their seemingly perfect relationship. What could possibly go wrong?

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. Because Jack Smith, the annoyingly attractive and broody older brother of her favorite client, turns out to be the cold-hearted experimental physicist who ruined her mentor’s career and undermined the reputation of theorists everywhere. And that same Jack who now sits on the hiring committee at MIT, right between Elsie and her dream job. Elsie is prepared for an all-out war of scholarly sabotage but…those long, penetrating looks? Not having to be anything other than her true self when she’s with him? Will falling into an experimentalist’s orbit finally tempt her to put her most guarded theories on love into practice?