Level 5
"The Singularity"
Level 5 is a large level that resembles a remix of "The Hotel" and "The Windows". It begins in a Reception area, slowly transitioning to the main section of the level.
In-Game
One can firstly pick up the ringing phone once spawned in. After listening to the instructions, you should proceed to the main area and therefore locating a door with a keycard reader usually found OUTSIDE of the hallway area (staircases, at the beginning of the section). Remember that, as you'll need to go back there later.
While exploring the hallways & floors you will eventually find a room with a children's carpet outside of the room. Enter the room and you shall find the keycard lying on the bed, or on the floor. IF the keycard is not there, it could either be in the proximity one floor above or below.
Exiting requires you to go back to the Security Room (with the Keycard picked up of course), interacting with the reader and proceeding to Remote Unlock using the cmOS Camera System (and simultaneously locating the exit).
From time to time you will experience connection losses from the cameras, shall you encounter a disconnect you can simply reconnect. This is due to the poor cable management that Jack and the Bloom guys left behind. I guess it's up to Dave to eventually fix it.