“THE ADVENTURE OF THE MERCHANT OF MURDER!” Clark Kent crusades against the Top, an avaricious owner of a secondhand auto business who deliberately and knowingly sells cars in seriously bad condition.

Superman: While Lois and Clark are out for a drive, they witness a car crash. Clark's x-ray vision reveals that one of the cars in the crash, supposedly new, had worn out brake linings. Investigating the car dealer, Speed Motors, Superman discovers that their used cars are made from parts salvaged from wrecks.

Later, Lois and Clark visit Speed Motors attempting to learn more. Sid Speed, the owner, attempts to bribe them to keep them quiet, but they refuse and are thrown out. Outside, they meet private detective Jefferson Smith, who claims to be investigating the used car business. He offers Lois and Clark the use of his car to get back into town, but on the way Clark discovers that the brakes have failed. Pretending to fall out of the car, Clark changes to Superman and saves the situation.

Later, Superman follows Speed to a meeting with the mysterious Mr. Top, who is the head of the ring of used car dealers. After a fight, the building explodes and Superman is buried in the rubble after helping everyone to escape.

Back in his Clark guise, he and Lois are abducted outside the Planet building, and taken to meet Mr. Top, who turns out to be Jefferson Smith. Smith makes a second attempt to kill them by putting them in a hydraulic press. Clark manages to disable the press without arousing Lois's suspicions about his identity. As he changes to Superman and chases Smith, Smith attempts to escape in one of his faulty cars, which catches fire and kills him as he speeds away.

Contents

1. "The Adventure of the Merchant of Murder" (Superman)
2. "Crime's Caravan" (Vigilante)
3. "After School"
4. "The Adventure of the Secret Submarine" (Three Aces)
5. "The Pied Piper of Doom" (Mr. America)
6. "The Flying Jeeps"
7. "The Dummy"
8. "Suddenly at War" (Congo Bill)
9. "The Case of the Maddening Music" (Zatara)