A riddle a day keeps the riddler away

S1 E11: 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.