King Boris, who hails from a European country, comes to Gotham City for a visit. Upon his arrival, there is a disturbance, which includes a clue from the Riddler. Batman and Robin investigate and get on the Riddler's trail. They are trapped by the criminal, who ties them to large wheels that will spin with ever-increasing speed until they are dead.

Batman manages to escape the Riddler's death trap. He and Robin decide to lay low until they can figure out the Riddler's caper. Meanwhile, the Riddler frees King Boris, who brings a gift to a major monument in Gotham City. It turns out the Riddler has substituted a bomb for King Boris's gift and he is demanding a ransom. The Riddler, though, overplays his hand, enabling Batman and Robin to capture the Riddler and his gang.