Esther Solar's family is unusual. Her father hasn't left the basement in 6 years. Her brother is terrified of darkness. Esther isn't afraid of anything, a feat she achieves by avoiding pretty much everything. Elevators are off limits, as are open spaces, crowds, family pets, birds, needles, haircuts, dolls and mirrors. Then Esther is mugged by her old classmate, Jonah Walker. Jonah is just as she remembers him: rude, cocky and from a broken family. He's also utterly fearless. Jonah's theft brings their lives crashing back together, and Esther and Jonah become surprising friends. Jonah sets a challenge: every week they must work their way through the world's 50 most common phobias.