A sniper, M'Naku, has Aquaman, the Batman, and the Green Arrow in his sights. At the last second, the Green Arrow sees the sun glint off the barrel, and scatters the heroes. The Green Arrow disarms M'Naku, while the Batman attacks. Once M'Naku is subdued, Aquaman interrogates the would-be assassin. M'Naku reveals nothing. The Sensei, of the League of Assassins, angered at M'Naku's failure, tasks Merlyn with carrying out the assassination.
Television anchorman, Clark Kent, is out on assignment, tasked with filming a news documentary on pollution. Kent asks the Atom to accompany him, as his assignment will take him near to Porttown, where Aquaman, the Batman, and the Green Arrow went missing. Merlyn disables Kent's news van. Kent confronts Merlyn, as Superman. Using specially designed arrowheads, Merlyn subdues both Superman and the Atom. Merlyn assassinates M'Naku.
The trademark arrows, and distinctive laughter, tip off the Green Arrow to Merlyn's presence. Earlier in his career, the Green Arrow faced off against Merlyn, and lost. Aquaman, the Batman, and the Green Arrow track Merlyn to an abandoned house. Suddenly, Aquaman collapses from extreme dehydration. Using his size and weight control belt, the Atom disables the arrow immobilizing Superman. The Batman submerges Aquaman in a fountain, until the King of the Sea recovers.
The Batman suspects that the Deadman has taken possession of Aquaman's body. The Green Arrow is caught inside a vacuum tube. The Batman hurls a batarang at the tube, to no effect. Still recovering his strength, Superman, and the Atom, hitchhike to Porttown. Spying the Green Arrow's dilemma, Superman hurls the Atom at the vacuum tube, shattering it. The Green Arrow squares off against Merlyn. This time, the Green Arrow is the victor.
Having failed to assassinate the Batman, Merlyn flees, knowing that the League of Assassins will be coming after him for his failure. The Batman confirms the Deadman's presence inside Aquaman. After a brief conversation with the Batman, the Deadman departs Aquaman's body. Alarms alert the Black Canary that something is interfering with the Justice League of America's teleportation system.
Hawkman, and the Flash, teleport up to the Justice League of America's satellite headquarters, but never arrive. Black Canary alerts Superman to the situation. The Batman brings Aquaman up to speed, regarding the Deadman and the League of Assassins. The Sensei makes plans to exact his revenge on the Batman.
This story was originally published in Adventure Comics #40 (July, 1939). A plot summary for this story can be found at the link.
This story was originally published in Adventure Comics #61 (April, 1941). A plot summary for this story can be found at the link.