The Water Horse: Legend of The Deep - Plot

Plot

In present-day Scotland, an American tourist couple go into a bar where they meet an old man who tells them a story about the Loch Ness Monster.

In 1942 Scotland a boy called Angus MacMorrow lives in a large manor house on the shores of Loch Ness with his mother Anne (housekeeper), his sister, a cook, a maid and an old game keeper. Later they are joined by Lewis Mowbray, who comes to work as a handyman in the manor. Angus' father—a sailor in the Royal Navy—is missing since his ship has been sunk in the war. However, Angus is unable to accept that he may be dead.

One day, while looking for seashells in the tidepools (in the movie the loch is saltwater), he discovers what appears to be a large mysterious egg. He leaves it in his father's shed and returns later to check on it. An unknown creature hatches from it whom he calls 'Crusoe' after Robinson Crusoe, that becomes the fabled Loch Ness Monster. Angus keeps the creature a secret, but eventually tells his sister and (reluctantly) Lewis about it. Lewis explains to Angus that it is a "Water Horse" and that it could be a boy or a girl, that it lays one egg, then dies before it can see it hatch. The next day troops of the 12th Medium Regiment Royal Artillery arrive at the house. They are commanded by Captain Thomas Hamilton a friend of Lord Killin, the owner of the house who is serving with the Royal Air Force. An artillery battery is set up near the lake as defence against possible attacking or hiding German U-boats and the troops set up camp on the grounds of the house. An anti-submarine net is also raised at the mouth of the lake to prevent the entrance of German U-boats into the lake. Meanwhile, Crusoe grows so fast that hiding him becomes impossible and eventually Angus has no other option but to allow Lewis to take it to the lake.

Captain Hamilton persuades Angus' mother to allow him to teach Angus some discipline and make a soldier out of him. She agrees but after a few days Angus escapes and returns to the lake where he left his friend. Crusoe lets Angus ride on its back. After some time, it begins to dive underwater, coming to the surface from time to time for breathing. Angus, having aquaphobia, loudly protests that it should stop diving, but later enjoys himself, perhaps even overcoming his phobia for the sea. The peaceful setting doesn't last long; Crusoe suffers from shell shock after almost getting shot by "Victoria" (a cannon; originally meant to stop submarines) aimed at the lake during a firing demonstration. Angus interrupts the demonstration to save Crusoe from getting killed. This upsets Hamilton and Angus' mother, who sends him to his room for a month as punishment for causing the disruption.

Two people who previously saw Crusoe while fishing on the lake attempt to take a photo of it in order to become rich. When they realize that they won't be able to photograph the real thing due to the bombardment test, they decide to create an imitation, which results in the real-life faked picture of The Loch Ness Monster, also known as "The Surgeon's Photo".

The photo, however fake, piques the interest of a few soldiers who venture out on the lake at night to kill it. The surprise attack proves futile for the soldiers, as Crusoe easily capsizes their boat. Angus attempts to calm Crusoe down and wades into the lake where he loses his footing and sinks. Crusoe comes to Angus' rescue and saves his life. After much coaxing from Angus, Crusoe decides to leave the loch for shelter and safety. However, guns from the nearby Artillery battery open fire upon Crusoe, mistaking it for a German U-Boat. Crusoe attempts to jump over the anti-submarine net but instead crushes it with its weight and escapes from the lake also causes all their guns to blow up again. It is implied that Angus finally accepts that his father may never return home while he sees Crusoe's departure from afar, along with Lewis and his family. (The story ends with the fact that, while several people claim to have seen Crusoe over the years, Angus never saw it again and yet never doubts that it was real.)

After the story was told (it is revealed that the story teller is Angus himself), a mother calls out to her son, who is walking down the beach and spots a rock. The rock looks similar to the egg that the water horse, or 'Nessie' as known in modern times, had hatched from. The last thing that is heard in the film is a crack from the egg, hinting to the viewers that Crusoe has died, but not before leaving a descendant behind to be the next Nessie.