Plot happens on your way out the door, though. Once you have the ability to do so, run for the door directly behind Demichev, sprinting whenever possible, and go through each open doorway you see.

After that, you'll be back on Katorga-12 in the E99 Processing Facility, along with Barisov. He'll tell you about your next mission: finding a way to charge and detonate the E99 bomb. When you leave, ...