Episode 7: Glass Houses
In the beginning of this episode you need to break into a mansion and plant a bug on the upper floor. This will trigger a cutscene and lots of enemies will arrive at the mansion. Go back downstairs and to the gym. Inside the gym is a hidden panel on the wall. Interact with it to open Roark's secret room. You can only interact with it after planting the bug on the upper floor. It won't work when you first arrive in the mansion (because the power is out).