The Last House

Jason Delgado, an unemployed engineer, is fishing when he sees an unusual-looking inbound storm. Just as it starts to rain, Jason returns to his suburban Seattle home where he lives with his wife Ann, their two children Graham and Ruth, and the family dog Cassidy. When they try to leave, they discover that none of their doors or windows can open, their internet and phones no longer work, and their neighbors are similarly trapped, while others are stranded outside. Jason tries breaking through the windows, walls and floor, but the water has created a barrier that prevents exit on all sides.

The electricity still works and they have water, but after two days of no change Jason and Ann begin rationing food and water, and set up activities to keep Graham and Ruth busy, which includes simple survival skill lessons. Over the following weeks, Ann works on an indoor vegetable garden and Jason builds a water reclamation system. Ruth notices a creature outside when it rains that she believes is friendly, but when she mentions this to her family they initially dismiss it as her imagination.

Two months after getting trapped, one of the outsiders, their neighbor Susan, arrives at the house yelling that there is no one left before being attacked by one of the creatures. In the aftermath, Jason and Ann implement a routine to hide themselves from view when it rains, as this is when the creatures are active. When the house's chimney cap falls in, they hoist Ruth up the chimney. Although Ruth is too big to go out, she confirms that the opening can access the outside. Cassidy gets sick when his medicine runs out; Jason shoots him and keeps his remains in the freezer.

Jason, with Graham's help, builds traps that he sends out through the opening to capture small animals that are now wandering the suburb, using Cassidy's remains and Ann's vegetables as bait. The power grid eventually collapses.

Five years later, they've expanded Ann's garden through the living room floor and their water systems are set up through the house. Despite Jason and Ann's efforts, Graham and Ruth are struggling and feel that survival is pointless. One day a creature with tentacles and dripping seawater enters their house, and although it does not find them, it poisons their garden and water supplies. Ruth deduces that the creatures are from the ocean and are reclaiming the planet.

When helping with a trap, Ruth is bitten by a ferret and gets an infection. Desperate to go outside, Jason follows the cracks in the house's floor and finds an opening, as the house is sinking and the water barrier has shifted. Ann uses the sewage pipes to get antibiotics from their dentist neighbor Max Richardson’s house, and encounters a creature while escaping, forcing Jason to seal the opening behind her. Knowing that the creatures will come for them, the family fashion weapons and traps in the hopes of escaping.

The next time it rains, water floods the house from the pipes, forcing the family upward to the attic. A creature enters their house to attack them and they manage to trap it. Jason stops short of killing it when Ruth insists. At the show of mercy, the creature opens the front door to let them leave and tells the other creatures to leave them alone before the house collapses into a sinkhole. The rains stop and the Delgados find Seattle almost totally submerged in water. The family sets off on a salvaged boat to travel the now-flooded planet, eventually finding other survivors.