Undergrowth

You play as Morgan, who is an undercover cop on an expedition as a camp guide-in-training far out in the mountains. You make friends within the camps, searching for answers regarding your lost comrade, who was also undercover before they were wiped off the radar.

In time, you realize that everyone starts developing a strange infection and you discover that its source is right at the heart of the research center near camp.
Some kind of mold has been growing, and it's not pretty. No back ups have been called, and you're essentially stranded for months.