Subway / David Munshi's laboratory | Riddles and puzzles SOMA Guide and Walkthrough

The first hidden hint - access code to the doors.

You will end up in almost pitch-black room, so it would be wise to hit the light switch on - it can be found on the wall, to the right of your current position. As soon as the room is lit, head towards the desk located in the corner of the room. Here you will find a computer, from which you will have access to a number of emails - there's nothing to send here this time though. In the upper drawer of the desk there's a note - check it out to find a access code (2501), which will be used very soon. Put down the note, open the middle drawer and read the article - afterwards head towards the nearby door.

Enter the access code to unlock the passageway.

Interact with them and then wait for a short while, until the main character tries calling David Munshi. After regaining control over Simon, interact with the control panel next to the door - enter the access code (2501) you've collected recently, open the door by pulling on the handle and enter the hallway.