Admiral Nelson has accepted an assignment to deliver classified material to a secret research facility located under the waters of Loch Ness in Scotland. When he arrives, he learns from the sole survivor, MacDougall, that the Loch Ness Monster has destroyed the facility. MacDougall is prepared to accept the material and carry on the work, but Nelson needs to learn the fate of the scientists. Following MacDougall's guidance, he takes Seaview
through a deep underwater channel and into the Loch.