From the #1 bestselling author of The Fault in Our Stars

When Margo Roth Spiegelman beckons Quentin Jacobsen in the middle of the night--dressed like a ninja and plotting an ingenious campaign of revenge--he follows her. Margo's always planned extravagantly, and, until now, she's always planned solo. After a lifetime of loving Margo from afar, things are finally looking up for Q . . . until day breaks and she has vanished. Always an enigma, Margo has now become a mystery. But there are clues. And they're for Q.

Printz Medalist John Green returns with the trademark brilliant wit and heart-stopping emotional honesty that have inspired a new generation of readers.