You find yourself at the entrance of a dark stairwell, containing many surreal secrets within its depths. You are a Class-D personnel, sent by the SCP Foundation, an organization dedicated to containing and researching anomalous beings, objects and locations. Your assignment is to recover an artifact brought into SCP-087 by a previous Class-D personnel, the details of which are classified.

SCP: Operation Descent is a first-person survival horror game based loosely on SCP-087 and the SCP Foundation, expanded to include new areas outside the stairwell. A mysterious entity lurks in the darkness, and your only options are to run or hide.