Dr. Mid-Nite meets London's Chief Inspector McReady at a bank where Police officials found the vault emptied, and a silver skeleton key left at the scene. Dr. Mid-Nite chases the crooks into a dense fog, and they then board a train, where he captures them with a Blackout Bomb. Meanwhile, the Flash meets the Parisian Commissaire of the Surete, who explains that the famed gargoyles atop the Notre Dame Cathedral have been disappearing. The Flash sets a trap, follows the crooks to a club where the crooks are emptying the treasure-filled gargoyles, and turns all over to the Surete.; Four famous detectives are invited by the JSA to Civic City to attend a meeting at the Civic City Palace Auditorium, wherein the crime detection methods used in their various nations will be used to "solve" a crime committed in their presence. After solving the staged crime, the four detectives disappear msteriously, with the clue of a silver skeleton key left behind. When the JSA receive urgent telegrams from their home nations to return home to solve a mysterious crime, the All-Stars realize a master criminal is at work and set out to find the detectives as quickly as possible.; Wonder Woman decides to employ Turkish psychology to round up a fake Emir who has made off with 300 pounds of gold, leaving a silver skeleton key behind, Using her invisiable plane, she spots a submarine, and brings it ashore, rounding up the crooks. In Honolulu, multi-millionaire J. Fred Wallis has had his "short-snorter" $100,000 bill, signed by celebrities, stolen, so G.L. hurries aboard, and using Harry Wan's methods of not hunting for the criminal, but making the criminal come to him, rounds up his suspect, turns him over to the Police, and then hurries back to Civic City.; When the JSA arrive back at the now deserted Civic City Arena, Black Canary tells them that she, Hawkman and Atom discovered a phony cellar below the arena stage, where they were attacked by a gang. After turning them over the the Police, the JSA discovers clues dropped by the missing detectives, follow them, and find the men around a table in a trance in a mansion. An image of Dawes suddenly appears on a screen, who then unmasks, revealing the true face of the Key. The JSA watch him attempt to flee in a cable car, but Wonder Woman stops it and the Key jumps 1000' to his death!