The portals themselves also became extremely unstable, and their connection to Earth was eventually severed. However, the Soviets' overuse of the portals and the planet's resources caused the green moss to gradually die out, which led to the portal mutating the remaining lifeforms on the planet to become hostile towards the colonists.

To compensate, the previous inhabitants had constructed a second 'exit' portal that led back to Earth, which was discovered by the Soviet colonists and used with the entrance portal to receive resources and new colonists. The entrance portal was eventually discovered to be only one way, constructed in this manner by the planet's previous inhabitants due to the times between the planet and Earth being out of sync (Earth is hundreds of years ahead of the planet). Wanting to use the planet to establish a 'new Motherland' for their people, the Soviets kept their discovery a secret as they began colonizing the planet. The planet was originally filled with bountiful lifeforms, among them a strange type of green moss that acted as the primary energy source for the planet's native lifeforms (which the Soviets adapted as their main source of electricity on the planet). In 1974, the Soviets discovered a portal in Siberia which led them to the planet. Through audio recordings left behind by the Soviet colonists, the protagonist is able to piece together what occurred on the planet.

As the protagonist makes his way across the planet in search of answers, he finds out he is not alone and the only other survivor is a mysterious Russian woman named Aelita who guides him through the planet's eerie landscape. As he explores through the planet, he occasionally receives hallucinations and flashbacks of his life on Earth. The game follows the protagonist as he explores the planet, figures out how the Soviets managed to travel to the planet and why the outpost is now empty, and why the planet is devoid of life. The mission is a failure as the ship is lost in the crash, both of the other crew members are killed, and the planet turns out to be an enormous wasteland seemingly completely devoid of life however, among the vast emptiness is a derelict Soviet Union science outpost constructed on the planet. The game follows an astronaut on a trip to another planet that is thought to be filled with lifeforms.

Lifeless planet premier edition trailer