With humor and insight, #1 New York Times bestseller Becky Albertalli explores the nuances of sexuality, identity, and friendship in this timely new novel. Imogen Scott may be hopelessly heterosexual, but she's got the World's Greatest Ally title locked down. She's never missed a Pride Alliance meeting. She knows more about queer media discourse than her very queer little sister. She even has two queer best friends. There's Gretchen, a fellow high school senior, who helps keep Imogen's biases in check. And then there's Lili-newly out and newly thriving with a cool new squad of queer college friends. Imogen's thrilled for Lili. Any ally would be. And now that she's finally visiting Lili on campus, she's bringing her ally A game. Any support Lili needs, Imogen's all in. Even if that means bending the truth, just a little. Like when Lili drops a tiny queer bombshell: she's told all her college friends that Imogen and Lili used to date. And none of them know that Imogen is a raging hetero-not even Lili's best friend, Tessa. Of course, the more time Imogen spends with chaotic, freckle-faced Tessa, the more she starts to wonder if her truth was ever all that straight to begin with. . .