‘SPOILER ALERT’

A young boy named Angus decides against going into the sea to swim, but chooses to sit alone at the shore, suddenly, he sees a large egg inside the water and picks it up.

As he’s taking a look at it, his mom, Anne, comes to get him so they can go home. Angus keeps the egg inside his bucket, and starts walking with Anne, who complains that he didn’t even try to get into the water.

Angus doesn’t say anything, and as they get home, he walks into the workshop in the house. His sister, Kirstie, soon arrives and asks Anne how things went at the shore, and if Angus had some fun. Anne says Angus remained his usual lonely self, and didn’t even get into the water.

Meanwhile, Angus drops his things inside the workshop, which happens to be that of his father, Charlie. Charlie is a soldier who is currently away from home, and helping his country fight in the war.

Angus takes a look at Charlie’s pictures, and also checks the calendar to see when Charlie will be back. After doing this, he goes to wash the large egg he found earlier. As he breaks off the top layer, he sees a shiny blue layer, and looks curious. Before he can break it further, he hears Anne calling him, and he has to leave the egg and run inside.

That night, rain starts falling heavily, and Angus realizes that the egg will not be safe in the workshop. He goes down there only to find out that the egg has hatched.

As he looks around to see what came out of it, he finds a weird creature. As he tries to touch it, the creature almost bites him, and he realizes that it probably needs something to eat.

Angus goes to get something for the creature to eat, and this calms the creature and makes it more friendly. Angus is unable to spend more time with his new pet, because he hears Anne calling him again, and has to run back to bed.

The next morning, Angus wakes up to see some soldiers arriving at the house. He goes down together with Anne and Kirstie, and they meet Captain Hamilton, who says he has brought his men to stay in the house to prepare an attack for an enemy, that might try to enter the country through the sea.

Anne is surprised by this, but Hamilton says it’s likely that headquarters forgot to send her a notice. Anne says she doesn’t have enough helps in the house, but he says his men can do all the work.

After they start arranging the house, Anne tells Kirstie and Angus to leave the men while they’re at it. On the way to their room, Angus asks Kirstie if she can keep a secret, but even though she says she can, she doesn’t give him enough time to say what he wants.

Angus then goes to the library to find a book about the creature he found. He goes to the workshop, only to see it scattered, with the creature also trying to eat Charlie’s shoes. Angus realizes that it needs food, so he goes to the kitchen to get something.

However, he meets the soldiers’ cook, Sergeant Strunk, who says he’s not allowed to be there. Angus explains that he needs some food, but Strunk doesn’t want to be bothered. Angus then asks to take out the trash, and Strunk agrees. With this, Angus is able to feed his new pet with leftovers and food items in the trash.

The creature starts eating it, and Angus watches happily. He names it Crusoe, and then starts reading about the creature, but doesn’t find anything concrete. Soon after, Crusoe finishes all the food, and Angus fills up the bin with water, so that Crusoe doesn’t get all dried up.

Meanwhile, Hamilton starts giving instructions to his men about how they want to approach the enemy, and make the first attack. Elsewhere, Angus soon has to leave Crusoe in the workshop, so that Anne doesn’t start suspecting anything.

However, a man named Lewis arrives to the town, and comes over to meet Anne while she’s checking the workshop. He says he’s the one who wants to work at the workshop, and even though she says he’s late, she tells him that he’ll have to clean up the whole place.

While he’s cleaning, he takes out the barrel which Angus had left Crusoe in. Angus sees this and immediately runs to stop him, but Crusoe isn’t there. Angus then asks Lewis questions about who he is and why he’s there, because it’s his dad’s workshop, and he’ll be back from the war soon.

Lewis says Angus’ dad can do anything he wants when he returns, but in the meantime, he’s the owner of the workshop. Angus leaves and starts looking around for Crusoe.

Interestingly, Crusoe has made it into the house, and Strunk’s dog, Churchill, starts running after it. Luckily, Churchill is chained, so he doesn’t succeed in pouncing on Crusoe.

Crusoe runs away and enters the bathroom. Kirstie enters the same bathroom, and as she screams and runs down the stairs, Angus realizes that she must’ve seen Crusoe.

He stops Kirstie from shouting and says Crusoe is his pet, and he got it from an egg he found on the shore. Kirstie still looks worried, but Angus begs her not to tell Anne, saying Crusoe is friendly and harmless.

Meanwhile, Anne goes to meet Lewis at the workshop. She brings some of her husband’s clothes and offers them to him, but this forces him to ask if Charlie is not coming back.

Anne says he’s not coming back, and Lewis apologizes, saying Angus had implied that his dad was still coming back. Anne says Angus is a confused boy, and Charlie is dead after his ship sank in the sea. She then tells Lewis to help her fix a plumbing problem in one of the bathrooms inside the house.

Lewis agrees, but the bathroom happens to be the one where Angus and Kirstie are hiding Crusoe. As Lewis knocks, they try to stop him from coming in, but when he says he’ll report them to Anne, Kirstie opens the door.

He comes in and tells them that Anne told him to fix a plumbing problem in the bathroom. Suddenly, he sees Crusoe and looks shocked as he asks what it is. Angus immediately explains how he got Crusoe. Lewis looks curious, but as he tries to touch Crusoe, it almost bites him.

Lewis then says Crusoe looks like a water horse, which is one of the rarest creatures in the world. He says there can only be one water horse in the world at a time, and when the old one dies, another egg is hatched to give rise to another one.

As he continues to talk about how it has possible magical abilities, Anne knocks on the door. Angus begs Lewis to help them hide Crusoe, because Anne won’t let him keep it. Lewis agrees, and as she enters, she doesn’t see it even though Crusoe tries to jump out of its hiding spot.

As Anne leaves, she meets Hamilton, and he invites her to join him for the dinner he’s planning with his men. That night, Lewis tries to tell Angus that they need to get Crusoe back into the sea, because that’s what’s best for the creature.

However, Angus disagrees, saying the best thing for Crusoe is to stay with him.

The dinner at the house soon starts, and Angus has to leave Crusoe in the bathroom to go and check something. But the door doesn’t get shut, and Crusoe is able to sneak out.

Churchill senses Crusoe’s presence and starts looking for it. The dog sees Crusoe and chases it around the house. They also disrupt the dinner and scatter everywhere, though everyone only sees the dog.

Crusoe heads out and jumps into the fountain, when sees a lot of fish in there. As Angus searches for Crusoe, Lewis tells him to go back into the house, because Anne is very angry about what happened at the dining table. He says he’ll find Crusoe, and Angus finally heads back in.

Shortly after, Lewis sees Crusoe in the fountain looking bigger. He goes to call Angus, and when they see it, they decide that they must take it back to the sea.

They put Crusoe in the back of the truck, and they head to the sea. On their way, Lewis tells the story of a water horse that had an encounter with a traveler who got lost. He, however, says he doesn’t remember if the water horse helped the traveler get back home, or just took him underwater.

They soon get to the shore, and Crusoe is released into the water. Angus doesn’t look happy with this, but he has no choice and lets Crusoe leave.

When Lewis returns to the workshop, Hamilton is there, and he says he’s starting to think Lewis is a bad influence on Angus. Lewis doesn’t let himself be intimidated, and says he doesn’t care what Hamilton thinks.

The next day, a man named Jimmy and his friend, Hughie, are out on a fishing trip. Suddenly, Hughie feels that the hook has caught something really big.

As they try to pull it out together, their boat gets pulled instead, and they soon see Crusoe looking much bigger. Jimmy and Hughie look terrified, but Hughie still wants to catch the big creature, because it would bring them a lot of money.

Jimmy doesn’t agree with this, and as Crusoe keeps dragging them further away into the sea, they decide to cut the fishing line. As Jimmy does this, they see Crusoe again, and can’t seem to believe their eyes.

Days later, Hamilton tells Angus that his mother wants him to be enlisted for service. With that, Angus starts working for the soldiers in different ways. Soon after, he gets tired of everything, and when the captain is distracted, Angus runs out to the shore.

He calls for Crusoe, but when he doesn’t see him in sight, he enters a boat and paddles himself around. Crusoe eventually reveals himself, and he has already become so big that Angus looks shocked.

Angus soon jumps on Crusoe’s back, and even though he’s terrified at first, he enjoys the ride around the sea. Crusoe also takes him underwater, and he enjoys it as well.

Just as Crusoe returns Angus to the shore, Churchill is nearby and senses him. Strunk is also with his dog, and as Churchill runs towards the shore, the sergeant sees Crusoe and struggles to believe his eyes.

That night, Angus narrates his experience to Kirstie and Lewis. They all laugh and seem to be enjoying themselves. Anne hears them and peeps through the door to see how happy they are.

Lewis sees her, but she immediately leaves. However, he’s fast enough to get to her and she thanks him for making the kids happy, because it has been long since she saw them smile.

He says it’s nothing, and as they continue talking, with the kids secretly watching them, Hamilton sees this and calls one of his men named Wormsley.

He asks him if he has gotten any information on Lewis, and Wormsley tells him that Lewis has a clean record, and nothing bad was found about him.

Elsewhere, Jimmy tells a reporter named Jock, about what he saw the other day. Jock thinks of it as a good way to bring investments into the town, because tourists would like to see the creature. However, Hughie says he doesn’t want that, and he prefers things the way they are. However, Jock says if there’s any monster in the sea, then the world must know about it.

The next day, Hamilton takes Anne and her kids to see the work they’ve been doing so far. They get to the top of a hill, and see all the weapons the soldiers plan to use against the enemy.

The captain tells his men to do a test run for Anne and her kids to see. Angus realizes that this will affect Crusoe, and he begs Anne to tell them to stop it.

Anne doesn’t understand what he’s saying, and she tells him not to disturb them. Kirstie tells Anne that Angus is not lying, but Anne still doesn’t understand them. Meanwhile, the soldiers start shooting into the water, and Crusoe struggles to avoid getting hit.

Because of this, Jimmy and Jock, who are also prepared to take a picture of Crusoe, are unable to get anything. They, however, make a fake object that looks like Crusoe and print it in the newspaper.

Days later, Strunk reads the newspaper and identifies the monster as what he saw the other day. With this, he and some other soldiers decide to set out to find it.

That night, Kirstie sneaks into Angus’ room and comes to help him leave the house with Lewis, to find out if Crusoe is doing okay. They leave the house, and when they get to the shore, Angus calls for Crusoe.

Crusoe doesn’t initially respond, but when it does, it appears to have gone wild. It doesn’t recognize Angus and tries to eat him. This surprises Angus and Lewis, who don’t understand what’s going on. Crusoe goes back into the water, and Angus blames Lewis for allowing them to send Crusoe into the sea.

Strunk and his fellow soldiers get on their boat, and start looking for Crusoe, who they plan to kill. As they get closer to the shore, they hear Churchill barking and Strunk says Churchill must’ve seen something.

He immediately asks that the boat be taken in the direction of the sound. Crusoe takes care of Churchill, and everywhere gets silent again. As the soldiers wonder what’s happening, Crusoe knocks them off the boat after they try shooting at it.

Elsewhere, the gunshots and attacks on the soldiers by Crusoe are mistaken as enemy fire, and Hamilton immediately gets informed that they’re under attack.

He asks all the soldiers to fight back, after which he tells Anne to get the kids and ensure they’re safe. Anne sees Kirstie and asks for Angus, but she explains that Angus is not in the house.

Anne says she can’t leave her son alone in the midst of an imminent attack. Even though Hamilton doesn’t want her to join him on his way to the shore, he eventually has no choice but to agree.

Meanwhile, Crusoe goes rogue and picks up Strunk, but Angus returns right in time to try to get Crusoe to stop. Crusoe doesn’t listen, and Angus goes into the water to get closer. He loses his balance and starts drowning, but this is enough to see Crusoe drop Strunk and save him instead.

After Angus is brought back to the shore, he is unconscious, and both Lewis and Crusoe try to wake him up, but he doesn’t respond. After several attempts to get Angus to wake up, he regains consciousness and looks happy to see Crusoe already back to normal.

Captain Hamilton is informed that there are no enemy ships in sight, but he still asks the soldiers to fire into the water. He soon reaches the shore, and Crusoe goes back to hide inside the water.

Anne gets down from the truck, and looks happy to see Angus. As he tries to explain everything about Crusoe, Anne gets angry and says he needs to stop talking about things that are impossible. Just then, Crusoe appears behind her, and she finally believes Angus, with Hamilton also looking shocked.

Suddenly, the soldiers start shooting into the water, and Angus jumps on Crusoe to lead him away. Anne is furious as she sees this, and she tells Hamilton to call off the attack.

He tries to do it, but the radios are down, so he’s unable to call it off. He, Lewis, and Anne are able to get on a boat to go after Angus. Crusoe successfully avoids getting hit, but as it gets closer to escape, the soldiers draw up a net that is meant to capture their enemies.

Crusoe is unable to cross the net in time, and as Hamilton’s boat gets closer, Lewis tells Angus to leave Crusoe and join them.

Angus calls Crusoe his best friend, and says he’ll miss him, after which he jumps into the water and joins their boat.

Crusoe then goes underwater and is able to get an extra boost to jump over the net, with Angus cheering as his friend now appears to be free.

When they all get back to the shore in the morning, Angus asks about his father, and Anne tells him that he is not coming back.

She also mentions that he doesn’t have to be worried about Crusoe, because it might be best for the creature to be alone.

Shortly after, they all then watch, as Crusoe departs and goes further away from the town.

After a while, a boy named William sees a large egg in the water, and just like Angus, he decides to keep it.

The Water Horse.