“The Quest for Cosmic Boy” begins! The Legionnaires have lost their longtime leader, Cosmic Boy-but was he captured by enemies or did he flee responsibility for his “war crime”? The Legion's newly elected leader makes a hard decision her first day on the job and sends out teams of Legionaires in search of Cosmic Boy. Will they be prepared for what they find?

Star Boy, Sun Boy and Mekt Ranzz have arrived on the planet of Winath to follow the trail of the missing Cosmic Boy. They are met by the United Planets Special Prosecutor, Tenzil Kem, who is in charge of the investigation of Cosmic Boy and if he's responsible for war crimes. Due to the rough climate of Winath, most buildings and businesses are below ground. The Legionnaires and Tenzil Kim cannot find anyone on the surface and go underground for any clues as to Cosmic Boy's whereabouts. It is underground that Mekt Ranzz comes across a symbol that says "Validus". Mekt gets angry, believing that Tenzil created the symbol, but it wasn't. Mekt then goes on to explain the importance of Validus, how he is considered the Lord of Lightning, and there's a cult based on him. Mekt was chosen to fulfill a prophecy of Validus and bring him to Winath, but failed in his endeavor. Meanwhile, Tenzil is met by twin children who tell him that they will lead him to the town's mayor but lead him into a trap, a silo filling up with wheat. The Legion members are attacked by the citizens of Winath who all appear to have lightning-based powers and are in the cult of Validus.