Superman's arch enemy, Lex Luthor, invents a giant-sized tuning fork, whose concentrated vibrations cause buildings to collapse and safes to crumble.; Superman investigates the disappearance of a noted explorer and discovers that a member of the Metroplis Museum Board has kidnapped the explorer and swindled the museum of hundreds of thousands of dollars.; Lois and Clark set out to investigate a series of vicious dog nappings, but it's Superman [whose secret identity becomes known to Lois' dog] who tracks down the true perpetrators of this racket.; Lois believes she is interviewing star Sari Mallon about a phony story concocted by her publicity agent, not knowing that a group of criminals are actually after the star's jewels.