It's a good thing for everyone involved that the war hasn't quite managed to give Severus the sort of shot nerves surviving Aurors have ended up with-- instead of startling, whirling around, and turning Hyperion into a writhing mass of curses and loud noises, Severus just stills for a moment.

Without turning around: "Making immediate plans to start locking the laboratory doors."

Leaving them open to prevent people being locked out without nanite access has been normal. But now. Finally Severus turns his head, staring at at him with a critical gaze. "What are you doing here?"