Phil Kelley, a well-known detective, makes the acquaintance of Cecil McLean during one of his raids and has been of assistance to the girl. Their acquaintance ripens and the two become very good to each other. The chief of police is very much disturbed at the operations of a gang of crooks known as the "Lumber Yard Gang," and after a particularly daring robbery, assigns Kelley to the case. Kelley examines the room where the robbery took place and finds a fingerprint of one of the crooks. By hard work he locates the crook's record and secures a photograph of him. Kelley takes a detail of police and starts on his mission. The gang hears that Kelley has discovered the identity of one of their members through the mysterious wireless system of crooks, and prepares to give the officers a warm reception. Kelley after placing his men in advantageous positions, goes alone to rout the crooks from cover and is met with a fierce resistance. A free-for-all battle takes place in which the officers join, and the crooks are finally routed. Phil picks out the leader and pursues him. Both pursuer and pursued exchange shots and both are wounded. The leader makes his way to a house and Phil closes with him. As he starts to handcuff his captive, the door opens and Cecil rushes out begging him not to take the man, as he is her brother. Kelley agrees to let the boy go if she will promise to make him leave town, and starts to return to his men. The chief of detectives has witnessed the chase, and when he sees Kelley return empty handed, upbraids him for cowardice and threatens to take his star away from him. Cecil sees them in an argument, and realizes that Kelley will suffer for his kindness to her. Determined to do the right thing she handcuffs her brother and goes out to summon Kelley. He and the chief meet the girl. She silently leads them inside the house and points to the handcuffed figure. The detective bends over the boy but finds that death has claimed him. The chief regrets his hasty words and leaves Kelley to comfort the girl, after telling him that he will hear more from the office for his successful handling of the case.