19-year-old taxi driver Ed Kennedy has little in life to be proud of: his dad died of alcoholism, and he and his mom have few prospects for success. He has little to do except share a run-down apartment with his faithful yet smelly dog, drive his taxi, and play cards and drink with his amiable yet similarly washed-up friends. Then, after he stops a bank robbery, Ed begins receiving anonymous messages marked in code on playing cards in the mail, and almost immediately his life begins to change. Usually the messages instruct him to be at a certain address at a certain time. With nothing to lose, Ed embarks on a series of 'missions'.

Zusak's protagonist, Ed Kennedy, unknowingly stumbles onto a mystery - or series of mysteries - that could very well make or break his life.