Five-year-old Dennis Mitchell is a real naughty and restless. He constantly invents some new tricks that just do not give rest to adults. Most often it goes to his neighbor, Mr. Wilson, who, being retired, likes to take care of his garden. One day, an unknown ragamuffin appears in their small town, who trades in petty thefts. Local residents, after the loss of things, begin to blame everything on Dennis, because he alone has a very bad reputation. The boy, offended by everyone, decides to run away and soon falls into the hands of the same tramp. However, Dennis is not a cowardly guy, and who knows, maybe the stranger himself will have to be afraid ?..