What happens
Clark Kent is trapped in a disabled submarine 250 feet below the surface after entering the escape hatch to investigate the cause. Commander Leed believes him dead, but the submarine rises and reaches the surface. Meanwhile, Lois Lane and Perry White are held captive in a cliffside house by a tall foreigner named Dr. Gruen, who threatens them and demands they choose whether to sail with him. Superman searches the coast by air for the missing submarine, which Kent believes was caught in steel nets on the ocean floor. The series is The Adventures of Superman, first aired May 16, 1941.
A disabled submarine 250 feet beneath the ocean, a cliffside house overlooking the sea, and the city of Metropolis
Characters: Clark Kent, Superman, Commander Leed, Lois Lane, Perry White, Dr. Gruen, Jimmy Olsen
Listen for: Dr. Gruen's ultimatum to Lois Lane, and Superman's search for the missing submarine along the coast
Written from the episode itself; it never gives away the ending. Every recording is remastered for the stream: cleaned of rumble, hiss and mains hum (and the old TV whine where we found it), then levelled in two passes to steady broadcast loudness, so one show is never quieter than the next.