Plot

A crew of oceanic researchers working for a deep sea drilling company try to get to safety after a mysterious earthquake devastates their deepwater research and drilling facility located at the bottom of the Mariana Trench.

An unknown, massive earthquake happens in a drilling station in the bottom of the Marianna Trench. A scientific crew must find their way across the ocean floor into another station under the threats of deep pressure, dark water, dangerous deep-sea creatures, and a constant lack of oxygen.—joel

The Kepler 822, a research and drilling facility operating in the depths of the Mariana Trench, is pushing its way into the centre of the Earth. When a mysterious earthquake strikes the site and destroys most of the deep-water station, mechanical engineer Norah and a handful of survivors must put on their heavy diving suits to walk across the dangerous, pitch-black ocean floor to find a way out. Now left with meagre choices, the deep-sea divers need to keep a clear head to deal with high pressure and the perils of meandering through the unrecognisable facility's scattered debris. However, the vast, unexplored ocean harbours deadly secrets--something strange is lurking in the abyss, awakened by the intruders.—Nick Riganas

In 2050, the mechanic engineer Norah Price is brushing her teeth at the drilling platform Kepler from Tian Industries in the underwater when Kepler starts to collapse probably because of an earthquake. She runs to the escape pods with her co-workers Rodrigo Nagenda and Paul Abel and learn that all the pods have been released and Captain Lucien is alone at the compartment. Under the command of Capt. Lucien, they flee to the control room, where the engineer Liam Smith and the biologist Emily Haversham are trying to contact the base on the surface. Capt. Lucien tells them that their only chance is to walk on the bottom of the ocean with the heavy pressurized suits to reach the platform Roebuck and use the escape pods. Rodrigo searches for helmets in good conditions and they use the cargo elevator to reach the floor of the ocean. However, Rodrigo's helmet is defective, and he implodes under the water pressure. Now, the five survivors need to reach Roebuck in a dangerous journey, and they find what has structurally damaged the Kepler.—Claudio Carvalho, Rio de Janeiro, Brazil

In 2050, the Kepler 822, a research and drilling facility operated by Tian Industries at the bottom of the Mariana Trench, is struck by what is assumed to be a strong earthquake. As part of the facility is destroyed by the incident, mechanical engineer Norah Price (Kristen Stewart) and her colleagues, Rodrigo (Mamoudou Athie) and Paul (T.J. Miller), make their way to the escape pod bay. The drilling facility is at a depth of 36,000 feet and pressure is at 8 tons per square inch. There have reports of strange sightings at the site before, but were dismissed by the Tian company. Anomalies include explosions, unexplained phenomena, and strange figures being seen. Kepler station is the command and control center for the Reobuck drill station.

However, the three discover that all of the escape pods have already been deployed, with Captain Lucien (Vincent Cassel) being the only person in the area when the three arrive. Together they reach a control base and find biologist Emily Haversham (Jessica Henwick) and engineer Liam Smith (John Gallagher Jr.), who are unsuccessful in their attempts to make contact with the surface. The power core of the Kepler station has lost its cooling and is likely to explode.

Lucien suggests using pressurized suits to walk one mile across the ocean floor to Roebuck 641 in the hope of resurfacing from there. To get to the surface of the ocean floor, the team has to take an elevator down. As they descend in a freight elevator, Rodrigo's defective helmet implodes under the water pressure, killing him. The surviving crew see a distress beacon from one of the escape pods below, and Smith and Paul go to investigate. As they arrive at the location, they find a body in the rubble. A creature emerges from the corpse's back and attacks them. Smith kills the creature and takes it inside. Haversham examines the creature and realizes that it belongs to a previously undiscovered species. The group believe that the drilling hit a hydro thermal pocket somewhere that had a heat source to sustain life at this depth.

The five make their way to the sea floor, but as they are walking, the Kepler explodes above and nearly buries them in debris. Smith is hit, but Price and Lucien save him. They manage to get through an access tunnel to an intermediate station, where they can charge and clean their suits. However, they find that Smith's oxygen scrubber is badly damaged from the debris. On their way through the access tunnel, Paul is attacked by an unknown creature, dragged underwater, and killed. At the midpoint station, the crew sees a 6000 tons drill bit shred to pieces. They believe that humans were not supposed to drill so deep into the ocean and now the ocean is taking back. Before the team leaves the access tunnel, they find that Smith's damaged oxygen pod will cause him to suffocate from the explosion's toxic fumes. Unwilling to leave another crew member behind, Price, Lucien, and Haversham agree to help Smith walk. The four set off across the ocean floor, but a humanoid creature appears and drags Smith into a cave. Lucien manages to get Smith out, but he is pulled from the other three. Price is dragged along with Lucien, but Lucien sacrifices himself to spare Price from the increasing pressure differential.

Price ends up at the abandoned Shepard station alone and is able to change her damaged diving suit before continuing toward Roebuck. Walking along the ocean floor, she reunites with Haversham and Smith, and proceeds to help drag Smith. As they enter Roebuck, they encounter a nest of the humanoid creatures hanging from the ceiling and try to sneak by, but the sound of Haversham's oxygen alarm wakes the creatures. Price is partially swallowed by one of the creatures but is able to kill it and free herself. The three manage to reach the escape pod bay, but Price discovers that only two of the pods are functional. Price and Haversham manage to get the ailing Smith into a pod, and Price persuades Haversham to take the last one. As this happens, a gigantic creature emerges and attacks the Roebuck while the smaller creatures follow the two escape pods. Price, accepting her impending death, initiates an overload of the Roebuck's nuclear core, resulting in a massive explosion that kills the creatures and allows the escape pods to reach the surface. This is followed by news headlines that say there were only two survivors, suggesting none of the other escape pods made it.

Tian Industries refuses to be involved with investigations into the events and prepares to expand its drilling efforts.