he author would like to acknowledge:

That disease and its treatment are treated fictitiously in this novel. For example, there is no such thing as Phalanxifor. I made it up, because I would like for it to exist. Anyone seeking an actual history of cancer ought to read The Emperor of All Maladies by Siddhartha Mukherjee. I am also indebted to The Biology of Cancer by Robert A. Weinberg, and to Josh Sundquist, Marshall Urist, and Jonneke Hollanders, who shared their time and expertise with me on medical matters, which I cheerfully ignored when it suited my whims.

Esther Earl, whose life was a gift to me and to many. I am grateful also to the Earl family—Lori, Wayne, Abby, Angie, Grant, and Abe—for their generosity and friendship. Inspired by Esther, the Earls have founded a nonprofit, This Star Won’t Go Out, in her memory. You can learn more at tswgo.org.

The Dutch Literature Foundation, for giving me two months in Amsterdam to write. I’m particularly grateful to Fleur van Koppen, Jean Cristophe Boele van Hensbroek, Janetta de With, Carlijn van Ravenstein, Margje Scheepsma, and the Dutch nerdfighter community.

My editor and publisher, Julie Strauss-Gabel, who stuck with this story through many years of twists and turns, as did an extraordinary team at Penguin. Particular thanks to Rosanne Lauer, Deborah Kaplan, Liza Kaplan, Steve Meltzer, Nova Ren Suma, and Irene Vandervoort.

Ilene Cooper, my mentor and fairy godmother.

My agent, Jodi Reamer, whose sage counsel has saved me from countless disasters.

Nerdfighters, for being awesome.

Catitude, for wanting nothing more than to make the world suck less.

My brother, Hank, who is my best friend and closest collaborator.

My wife, Sarah, who is not only the great love of my life but also my first and most trusted reader. Also, the baby, Henry, to whom she gave birth. Furthermore, my own parents, Mike and Sydney Green, and parents-in-law, Connie and Marshall Urist.

My friends Chris and Marina Waters, who helped with this story at vital moments, as did Joellen Hosler, Shannon James, Vi Hart, the Venn diagramatically brilliant Karen Kavett, Valerie Barr, Rosianna Halse Rojas, and John Darnielle.