Eighteen-year-old Ruby Santos, grappling with her mother's death and financial struggles, discovers her father's secret life as a magical underworld delivery person, leading her to take over his station and jump train lines, only to realize the perilous nature of the job and the dangerous world she has entered.

Almost a year after settling down in Oregon, Coyote embarks on a cross-country road trip with her dad to scatter her mom's ashes, but the journey takes an unexpected turn when she realizes the secret to the chosen resting place lies in a lost book.