Known only by his first name, Rudy is a developmentally disabled man who roams the streets of Annapolis, Maryland during World War II.. He lives in a tool shed in the woods near Spa Creek across from town, eating fish, crabs, and the small animals he traps. He also begs for money--rattling coins in a tin can--in front of the county court house. These are the days when secret weapons are being developed at the Naval Experimental Station, just across the Severn River. At times, a roar that shakes the whole town comes from the Station. By a quirk of fate, Rudy comes into possession of secret papers about this top secret project, and Russians spies are on Rudy's trail to get the pictures back. This is also a story of a typical American family of the 1940's, and how they try to save Rudy from the most formidable spy system in the world.