Nine
Nine has just arrived at the Security Room when the absence of something catches his attention. Those discharges from the damaged generator, he realizes, created an irritating, always present background noise, and now that noise is gone, replaced for a much gentler humming. "Well done, Charlie! Now let's go back. I'm worried about that sentry bot."
They enter the generator room together, and Nine notices several bodies and robots against a wall. But that's not his main concern. "That thing didn't move, right?" He asks. It's evident, however, that the sentry bot is deactivated. Not that surprising, considering the time it has been exposed to those discharges.
Nine gets closer to the bodies, observing the many bullet holes and laser burns on them and on the wall. "They are all unarmed. Someone collected their guns, or it was an execution." Looking back at the sentry, he recalls these robots sometimes are armed with a machine gun and a laser. "Maybe the sentry killed them." He checks the room, and particularly the bodies, trying to find anything useful.
PER check: 1d10+7: 16 [1d10=9]