In his second Monogram vehicle, William Cagney (James' brother) is teamed with rough-and-ready Robert Armstrong. The stars are typecast as Lucky Davis and Bob Owens, a pair of reckless high-explosive experts (hence the title). After several hair-raising adventures in the U.S., the story shifts to South America, where Lucky, Bob and their mutual chum Jimmie Pearson (Edgar Kennedy) get mixed up in a banana-republic revolution. The boys' thoughtless act of shooting off fireworks at a local political rally results in a series of disastrously comic consequences. The film's requisite dark-eyed senorita is played with mucho gusto by Maria Alba.