The film starts on an unexpectedly rainy day, when the family realizes they’re sealed into their house with no way of opening or smashing through the doors or windows. Meanwhile the family is growing increasingly hungry and grumpy with each other, as food runs low with no new signs of escape. One day during a big rain, a creature uses water powers to open the door to the house. The alien leaves before it can do much damage, but when it departs the family is still trapped inside. Water starts rapidly flooding the house, with a creature swimming through, clearly adept at moving underwater as had been predicted.