Tom and Wally Danger begin attending the Westfield school and join the football team. Together with Derrick Dawes (despite his original attempt at bullying them), Eagle and Butch, they win the last and toughest game of the season. Eagle calls them Tough Kids and they adopt the name "Tough Kid Squad", but the villainous Dr. Klutch abducts them all after the game, explaining that he was the enemy of the elder Dr. Danger.; Dr. Klutch examines the Danger twins and discovers the agent in their blood from their father's improvement serum. Meanwhile, the other three Tough Kids escape and rescue the twins. The kids start to fight their way out of Dr. Klutch's lab.; After a daring mid-air rescue of the pilot of a sabotaged plane, Red goes after the saboteur.; Dr. Danger and his wife are accidentally killed by the crossfire in a gang fight, leaving behind twin infant boys. Dr. Danger's friend Prof. Moxon adopts Wally and plans to try out his child-rearing theories on the lad, but Tom is abducted by the master criminal Wong Chee who intends to raise him as his apprentice. On their fourteenth birthday, Tom flees Wong Chee and after a brief case of mistaken identity is reunited with Wally.; Dr. Klutch explains that he was Dr. Danger's partner and is after his former partner's "improvement" serum that he tested on his twins. Dr. Klutch explains that he orchestrated the murder of Dr. Danger and his wife. While Dr. Klutch is distracted, the boys escape. They are later menaced by a madman but are rescued by Dr. Klutch who recaptures them.; Now enhanced by the serum, Dr. Klutch seeks to take over several crime gangs. But the Tough Kid Squad is on his tail for their final confrontation.; The Human Top hears of a train wreck and rushes off to help, only to find that it was caused by minions of the Red Terror who are looting the wreckage.; Dr. Klutch tests the serum on his brutish, tongueless servant Komba, but as the serum works on him and increases his intelligence, Komba rebels. Dr. Klutch tries to shoot him but just drives him back into the tunnels where the kids are trying to escape. Eagle defeats Komba but then they encounter the mad doctor, who takes another blood sample and now injects himself.