California plains in the 1850s. After losing his mother to cholera on the wagon train out west, Emmet Campbell mostly fends for himself in the boom town of Colusa, California where he and his busy and ambitious father settle. Coming of age for Emmet means hiding in the corners of his father's new saloon, scrounging for food in the local brothels and finding refuge in tunnels underneath Colusa's Chinatown. While fighting off town bullies, an evil Irish stepmother, and his own learning disabilities, Emmet struggles to find his footing but never loses his curiosity about the world around him and the people in it. When forced into a court case to establish his identity and rightful inheritance after the untimely death of his father, Emmet must find family and identity in places he might not have reckoned for. But can he? With equal measures of the dark and the light, Campbell's boy is a tender tale about a boy whose fractured beginnings lead him on a journey through life that reveals what it can mean to be human.