Peg and Korky plan to spend the summer helping their poor elderly friend, Mr. Barkley. Mr. Barkley lives in a dilapidated house without electricity. Peg and Korky help him by mowing his overgrown lawn and being his good friend. They plan on a quiet summer until businesses on Main Street get robbed - including Peg's father's business. A transient named Abe is the police's prime suspect. The cousins search the town for Abe and when they find him, they have many questions to ask. Abe must be the thief - when he came to town, the robberies started; when he left, the robberies stopped. Peg and Korky are close to identifying the thief when they receive a mysterious note from "A". The robberies begin again. But Abe left town...or had he?