You get this achievement in the chapter "Danger and Obliquity" (~chapter 32).
This achievement is timed, so the steps have to be done fairly quickly.
At the beginning of the chapter, Lucas has a vision that Markus is in danger. Quickly circle the bed and use the phone.
Your POV switches to Markus. Choose the option to answer the phone, then quickly head toward the door in the distance, go through and pick up the phone. As soon as the conversation is over, you have a short time to go to the door you just entered through and lock it. Once it's locked the timer goes away; return to the phone and the achievement will unlock.