12-year-old Mike Fowler lives in the minute community of Ambrosia, Arizona (a fictional town) with his single mother and his paternal grandparents. The family runs the Last Chance Gas and Diner highway stop near the town's municipal limits, as well as the small hangar and airstrip nearby. The diner property is also home to Lady Liberty, a B-17 Flying Fortress flown by Mike's grandfather in World War II; it is in the plane that Mike and his three friends – Ben Jones, Winona "Winnie" Whitefeather, and Spencer Williams – run their detective agency called the "Last Chance Detectives". Together, they solve mysteries and have adventures, while learning Christian morals.