Overview: Hal, Ed, and Gail plunge to the lowest depths of the ocean in a special crystal bell to plant a second seismographic signaling device after the first one mysteriously disappears.
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First Air Date: Sep 09, 1972Last Air date: Dec 02, 1972Season: 1 SeasonEpisode: 13 EpisodeRuntime: 20 minutesQuality: HDIMDb: 6.80 / 10 by 4 usersPopularity: 10.699Language: English