Runner by Carl Deuker

When Chance Taylor is offered a suspicious job -- retrieving packages hidden on his daily running route and stashing them away for later pickup -- the high school senior doesn't ask many questions. Chance views the two-hundred-dollar-a-week salary as a means to pay mooring fees for the sailboat where he and his alcoholic, chronically unemployed father live, as well as buy groceries and get an occasional muffin at the coffee shop where he spends time with his wealthy yet sympathetic classmate Melissa. Although he suspects he's working for a Puget Sound drug-smuggling ring, Chance doesn't get too worried until the nature of the packages begins to change and the man who hired him dies under mysterious circumstances.