Eleven year old Earnest wants the summer of 1952 to be adventurous. So he cons his friend, Nicholas, into believing a saint directs them to save the world from Commie spies. Earnest learns much from, Guys and Dolls, a book he finds in the garbage. Applying what he learns, Earnest cons Lucky Luigi, a bully, out of a dollar. But then their lives become complexicated.

After receiving a sign that the Commies are infilterating their Brooklyn neighborhood, Operation Top Secret is born. While investigating Commies Headquarters, Nicholas bumps into a thief who has just blown a mob bosss safe. After the thief drops the bag into a sewer, the boys fish it out and discover it contains sacred relics. Earnest and Nicholas hide from mobsters who will do anything to find the bag. Gutsy Gus helps the boys out of this and other jams. Suspicions increase when a limousine stops in front of the stoop and one very classy doll with a Russian accent pays a visit to Gutsy Gus.

On the Stoop shares the rollicking adventures of two Brooklyn boys as they investigate suspicious events while dreading an even bigger problem: the nuns at St. Marys.