Philanthropical druggist Daniel Abbott, occasionally robs the rich to take care of the poor, goes to court with his young ward, Jimmy Nolan. In the courtroom Daniel meets Mrs. Warren, who, despondent over her inability to care for a newborn baby, has been charged with attempted suicide. Daniel takes mother and daughter under his wing, watching with pride as the girl, Helen, and his ward, Jimmy, grow to a tender adolescence. Sylvester Doane, a tenement owner, falls in love with Helen, and Daniel makes plans to rob him. Jimmy learns with shock of the plans and goes to Doane's apartment to prevent the robbery. Jimmy takes the gems to forestall his father, but he is found with them in his possession and put in jail.

The film is based on a book of the same name by Arthur Guy Empey, detailing his service as an American volunteer with the British Army on the Western Front.

Grace Culver's sharp tongue, has garnered her with the nicknamed "The Wasp." A spirited disagreement with her canning magnate father, John Culver, results from Grace's refusal to marry Kane Putnam, her father's business partner, and she orders her new chauffeur, Tim Purcell, to take her and her maid Miller on a drive. On their return, they are captured by Brazsos, a German spy who plans to blow up her father's munitions factory. Grace learns of the hidden tunnel Brazsos has excavated to the factory, and as Miller escapes to alert the police, Grace unties the chauffeur and leads him to the tunnel. When the bomb explodes prematurely, Grace and Tim become trapped, and facing death, they confess their mutual love. The two are rescued, after which Grace discovers that Tim actually is wealthy Yale football star Harry Cortland, a revelation that delights her father.

Captain Mills is jealous of Jim Clifford, his fellow officer at the British War Department, so he steals an important document in an attempt to make Clifford look bad. Clifford has to undergo quite a bit to get the papers back, and his adventures take him to several fancy weekend parties, including one on a yacht, which wrecks. He discovers that Mills gave the document to Grace Weston, who doesn't realize what she's got.