You missed another bomb.
You and the others find yourself in a security center, there are monitors showing all of the rooms in the mansion (Some of them out for obvious reasons), sitting at a desk in a wheeled swivel chair is the Warden. Who turns and delivers a slow clap to you.
"Congratulations, you managed to get through my little obstacle course. And you only leveled half of the complex to do it. Seriously, I figured you would have given up after the first explosion, but points for determination if nothing else."