"A charming, tender, and hilarious debut you will want to get lost in." --Gayle Forman, bestselling author of If I Stay and I Was HereIn this ode to all the things we gain and lose and gain again, seventeen-year-old Penelope Marx curates her own mini-museum to deal with all the heartbreaks of love, friendship, and growing up. Welcome to the Museum of Heartbreak. Well, actually, to Penelope Marx's personal museum. The one she creates after coming face to face with the devastating, lonely-making butt-kicking phenomenon known as heartbreak. Heartbreak comes in all forms: There's Keats, the charmingly handsome new guy who couldn't be more perfect for her. There's possibly the worst person in the world, Cherisse, whose mission in life is to make Penelope miserable. There's Penelope's increasingly distant best friend Audrey. And then there's Penelope's other best friend, the equal-parts-infuriating-and-yet-somehow-amazing Eph, who has been all kinds of confusing lately. But sometimes the biggest heartbreak of all is learning to let go of that wondrous time before you ever knew things could be broken...