A unique find along the railroad tracks near a small town in North Dakota inspires four middle school boys to investigate its origin. As two strangers hide in town, the boys can't help but wonder if the two are up to no good and linked to their find.
Deevee Wagner, one of the four boys, takes the lead on their investigation. The four work together to answer questions they have, but trouble seems to follow them at every turn. Setbacks don't discourage them, and they still manage to keep their activity secret from the adults in their lives. . .for a time.
After a theft is reported in a nearby town, the boys know they are onto something. Events pile up, and the boys are forced to share what they know with the adults after an encounter with one of the strangers. The town's police officer aids in their undertaking, but he must discipline the boys for risky actions.
Deevee discovers he has the skills and insight to put it all together, but he will need the help of his friends and the adults in his life to work out his plans-to capture the thieves and recover the loot.