A criminal uses his son as bait to lure another gang to Lakeside City.
In 1945, a man was thrown from a motor boat into the waters of Lake Michamaw. This man drowned, desperately clinging to an iron box. Twenty-three years later, the iron box is accidentally recovered by a fisherman. The contents of the box prove ruinous to two men, industrial engineer, Harold Loomis, and famed archaeologist, Homer Gridley. Loomis is revealed to actually be the son of notorious mobster, Leo Locke. Gridley is revealed to have forged several of his "discoveries".
The revelation of Loomis' true lineage puts him in the sights of the Bulleteers, who mark Loomis for execution. To discern the identity of the informer, who revealed the contents of the iron box to the media, both Loomis and Gridley shoot at the editor of the local paper, Marley Thorne. News of the attack on Thorne is quick to reach his brother-in-law, police scientist, Barry Allen. Allen decides to investigate the matter, as the Flash. News of a bank robbery, by the criminal gang called the Pryotekniks, reaches the Justice League of America.
The Justice League of America confront the Pyrotekniks. The Pyrotekniks unleash their fireworks-firearms on the Justice League of America. The multi-hued lights of the fireworks-firearms have a myriad of effects on the Justice League of America. The Hawkman's wings are incapacitated. The Green Lantern's will power is disrupted, causing the Atom and the Batman to fall. The Flash rescues the Atom, the Batman, and the Green Lantern from their deadly plummet.
The Flash, though, takes a barrage from the fireworks-firearms, immobilizing him. The Hawkman drops down on the Pyrotekniks. His attack gives the Justice League of America a chance to rally, and turn the tide of battle. The Pyrotekniks are brought to justice. Locke is revealed to be the leader of the Pyrotekniks. Furthermore, Locke is the informant who provided the contents of the iron box to the media. That information, however, has placed Locke's son, Loomis, in deadly peril.
Locke begs the Justice League of America to save his son, from the wrath of the Bulleteers. The Hawkman uses his thermotector to track Loomis and Gridley to a cavern, outside the city limits. The Bulleteers had also discovered Loomis' whereabouts, but flee the scene when the Justice League of America arrive. The Justice League of America track the Bulleteers to their hidden fortress headquarters. After barely surviving a series of booby traps, the Justice League of America confront "Bullets" Jameson, and his Bulleteers.
An explosive=laden booby trap fells the Justice League of America. The Bulleteers are about to execute the Justice League of America, when Loomis and Gridley get the drop on them. Though outnumbered, Loomis and Gridley aim their guns at Jameson, himself, to coerce the mob boss into surrender. The Green Lantern melts all of the guns with his power ring. With the Justice League of America recovered, the Bulleteers are taken into custody. Loomis offers to financially back Gridley, to give the disgraced archaeologist the chance to redeem himself, in the eyes of his peers.