When Frederick Vincent Jr. runs away from home because his father doesn't like his dog Duke, the police think that he will return very soon, but Mr. Vincent is worried. Freddie hops into the back of a truck that night, unknown to its driver, gang leader Joe Calerno. After Joe commits a robbery, he discovers Freddie and throws Duke from the truck, but Duke quietly jumps back in and follows them to Joe's hideout where Freddie is a prisoner. When Joe orders his cohort Tony to kill Freddie, they discover that he has escaped, so the men drive off, except for Joe, who sees Freddie hiding on the roof and shoots, wounding Duke. Later taking pity on Duke, Joe takes him and the boy with him as he eludes the pursuing police, then takes him to a nearby veterinarian. When police arrive at the vacant hideout, they find Duke's collar and realize that the gang has Freddie. Meanwhile, Joe has taken the doctor and Freddie with him in the vet's van, but by the time the police realize what has happened, Joe has stolen another car and has taken only Freddie and Duke with him. Driving into the mountains, Joe desperately tries to elude the pursuing police and crashes his car, then escapes on foot, carrying the weak Duke. Joe now feels a fondness for the boy and his dog, so he tries to send Freddie away, but the boy won't go, preferring staying in the woods with Joe to returning to Vincent. Because Joe doesn't want to be accused of kidnapping, he tries to insist, but Freddie threatens to inform on him if Joe sends him back. Ten days later, the police ask Vincent to offer a $50,000 reward for Freddie, hoping that some of Joe's old gang will find him and turn him in. Freddie and Joe, who are having a great time camping out in the mountains, are unaware of the reward and are surprised when Tony and the others, who have secretly been followed by the police, arrive. When the gang takes Freddy, Duke follows and attacks one of them, Chi, who tells Joe where they went. Before Joe can chase them, though, the police apprehend him. Duke follows Tony's car and jumps on the roof, unknown to the gang. At their hideout, Duke sees Freddie, then goes for help and is found by the police. Despite the fact that Vincent believes Joe's story of devotion to the boy, the chief will not risk setting him free to find Freddie. When Duke turns up at the station and goes to Joe, Joe fakes a heart attack and, with Duke's help, escapes. Unknown to Joe and Vincent, the chief was allowing the ploy to work so that the gang wouldn't realize that the police were in on Joe's rescue scheme. That night, when Joe and Duke find Freddie in the gang's hideout, an abandoned tugboat, they don't know that the police are nearby. Joe gets the drop on the gang and escapes with Freddie, but Tony catches up with them, and in a struggle, shoots Joe. Duke then holds Tony at bay until the police arrive. As Joe dies in Freddie's arms, he tells Vincent what a swell kid he has.