At Lake Arrowhead, Evil Star and his gang suddenly appear on the set, but Flash and Dr. Mid-Nite battle them and chase Evil Star into an office, where they are captured. Elsewhere, a comedy sequence is being shot when Hawkman and Wonder Woman discover that a gun is loaded with real bullets, and that the "Keystone Cops" are really Evil Star's gang. The villain over-powers the duo. At Stellar Studios, Atom and Black Canary are on the set as Fanum instructs Guy Pompton to secure props for the next scene. When Evil Star sneaks away with silver ingots, the duo are lured into a trap.; A new crime expose film, "Thief in the Night," is in production when one of the cast disappears during a scene. Soon, producer Fred Fanum gets a warning note from a criminal named "Evil Star" to stop production at once, so Fanum calls in the JSA to investigate. Fanum tells them how a mysterious writer started providing only parts of the script so that production could begin, but he had not seen the final part. Dr. Mid-Nite deduces that the script may be factual, exposing the activities of a real criminal, probably Evil Star, who would stop at nothing to halt production on the film.; GL visits a ghost town where the scripts to "Thief in the Night" had been mailed from, and discovers the author at work, when Evil Star knocks the Emerald Crusader out. When he recovers, he and the other JSA members find themselves securely bound on the front row of a private theatre.....facing a knife-throwing machine, whose weapons are aimed at the JSAer's chests. G.L. muses that if all members move one way together, the knives thrown will miss them entirely, which proves true. The JSA return to the studios and accuse Pompton of being Evil Star, a battle ensues and he is captured.