2122.

In the mine shafts deep beneath the mining colony of Bowen's Landing, Kolton Brown searches for his missing colleague, Alan "Al" Reid. Kolton runs to inform others after discovering his corpse in the darkness.

The next shift arrives at the mine head on the surface. As they prepare, miner Clark Witchell expresses his anxiety about rumours. It seems that Weyland-Yutani is about to close the colony because of low returns. The others congratulate Lorraine Hawkes on the forthcoming birth of her second grandchild. In the control room, synthetic security officer Hanks and Mine Supervisor Bill Monroe (along with his dog, Dan) start their shift. They keep an eye on the new shift as they clock in and board the lift down into the main shaft. Amongst the new shift are Lorraine, Martin Rai, Ryo Kuan, Rex Parish, Miranda Jacobson, Tracy Rajamani, and Kenneth Rapley.

As the miners begin their descent, Hanks informs Lorraine that no one has found the fresh seam they're expecting to break into.

Lorraine briefly reunites with her daughter Anna when she arrives at the gallery, before Anna and the rest of the previous shift return to the surface. Kolton, terrified, informs the new shift he found Al, but can't bring himself to say what he saw. He instead invites them to come to see for themselves. So that Hanks can track their progress, the miners retrieve a portable camera unit from a nearby locker. Then, they follow Kolton back to Al's body.

When the miners arrive at Al's body, they see his chest split open, as if something had torn its way out from within. Examining the area further, they come across three big, egg-shaped items that appear to have been dug from the surrounding rock face. One of the eggs is open at the top. Lorraine concludes that whatever killed Al most certainly originated from the egg. She grabs a mining tool and intends to destroy them, but Hanks encourages caution and suggests that they flee the area while she alerts the corporation.

Hanks transmits a message to Weyland-Yutani as the miners prepare to remove Al's body. She then seals the control room door, preventing Bill Monroe from returning.

Something lurking in the shadows kills Clark before the miners can leave the scene of Al's death. The lights go out as the rest of the party can run. The kiande amedha kills Winni Mamani while she attempts to beat it off with an axe. Hanks watches the camera feed with a mixture of terror and awe in the control room. Unbeknownst to the miners, it is she who has turned off the lights in the mine. Despite Lorraine's meddling, the survivors return to the lift and begin their ascent, until Lorraine stops it.

Lorraine explains that the thing is now contained in the mine. If they return to the surface, there is a good risk it will follow them and escape into the colony where their families live. She refuses to let that happen and declares her plan to return and kill it. Hanks tries to persuade her to leave the monster alive so Weyland-Yutani can collect it. Lorraine refuses, revealing her loyalty to the miners.

Enraged, Lorraine breaks the portable camera, rendering the synthetic blind to what is going on in the mine. Hanks stares at the now-disabled camera stream in the control room. Then, a message from Weyland-Yutani flashes on an adjacent monitor, instructing her to secure the creature.

Lorraine goes back to the mine shaft by herself, armed with a rock drill. The thing materializes in front of her, lurking in the shadows. The rest of the miners gather around her as she prepares to face it, having concluded that she can not battle the beast alone. They hoist their mining tools before the beast jumps out of the darkness towards them.