Voyage to the Bottom of the Sea Season 4 Episode 19
Secret of the Deep
Naval ships have been disappearing, and Seaview is on a hunt for the undersea installation responsible. They find a sea-lab that is not only well-armed but surrounded by overgrown and ferocious sea-creatures. To complicate matters, the guest expert aboard is a traitor. Various "dangerous denizens" of the deep from earlier episodes reappear here, thanks to re-used footage: there's a whale, and one of those globular-eyed bottom-dwelling monsters seen in such episodes as "Deadly Creature Below".
- 4 - 26No Way BackMar. 31, 1968
- 4 - 25The Death ClockMar. 24, 1968
- 4 - 24Edge of DoomMar. 17, 1968
- 4 - 23Attack!Mar. 10, 1968
- 4 - 22Flaming IceMar. 03, 1968
- 4 - 21Savage JungleFeb. 25, 1968
- 4 - 20Man-BeastFeb. 18, 1968
- 4 - 19Secret of the DeepFeb. 11, 1968
- 4 - 18The Abominable SnowmanFeb. 04, 1968
- 4 - 17NightmareJan. 28, 1968
- 4 - 16The Lobster ManJan. 21, 1968
- 4 - 15Terrible LeprechaunJan. 07, 1968
- 4 - 14The Return of BlackbeardDec. 31, 1967
- 4 - 13Deadly AmphibiansDec. 17, 1967
- 4 - 12Blow UpDec. 10, 1967
- 4 - 11A Time to DieDec. 03, 1967
- 4 - 10TerrorNov. 26, 1967
- 4 - 9RescueNov. 19, 1967
- 4 - 8Time LockNov. 12, 1967
- 4 - 7Fatal CargoNov. 05, 1967
- 4 - 6Man of Many FacesOct. 29, 1967
- 4 - 5Sealed OrdersOct. 22, 1967
- 4 - 4Journey with FearOct. 15, 1967
- 4 - 3Cave of the DeadOct. 08, 1967
- 4 - 2The Deadly DollsOct. 01, 1967
- 4 - 1Fires of DeathSep. 17, 1967