Juvenile Court judge Bradley Page and child welfare officer Kay Linaker take an interest in Billy Lee and his pet, Ace the Wonder dog. Billy's mother has passed on and his father, ex-marine Addison Richards can't get re-enlist; he's old, and has a drinking problem. Ace, however, can enlist in training, and makes good, and Page promotes a job for Richards at the same defense plant that Ace is guarding. Between the two of them, they can deal with saboteurs!
It's a cheap little Monogram picture, and the writing is hit-or-miss, but everyone tries hard, and Ace, while he's no Rin-Tin-Tin, is a handsome beast with some good tricks. S. Roy Luby, like many a director who came up as an editor, knows how to cut in the camera, and so it moves at a decent clip.