Source plot synopsis — includes the ending
In the Crater, the protagonist is attacked and infested by a parasite, which allows the protagonist to use several weapons and machines, but regularly wounds it and sprouts tendril-like appendages that gradually cover the protagonist's body. The infested protagonist reaches a central elevator that has been enveloped by a massive creature with a vaguely humanoid head called "The Crater Queen". Reactivating the elevator apparently kills the Queen but allows the protagonist access to a monorail to reach a temple called Polis.
While the protagonist is exploring the temple, the parasite nearly fully envelops it, forcing it to use a machine to remove the parasite. During this process, it is heavily implied that the parasite is actually the first protagonist who mutated when the Assembly heart burst. Just before it is removed, the parasite disembowels the protagonist, who staggers to another medical device that connects it to an apparent hive mind within the temple. Controlling two androids called Shells, the second protagonist attempts to carry its own body towards a swirling energy field, but gets attacked and infected by the parasite before it can reach the field. With the parasite now merged with the protagonist, the two form a mass of seemingly immovable flesh.
Sources and content license
Source and revision history ↗ · Adapted from Wikipedia contributors, Scorn (video game). Section headings and formatting adjusted. · Content license