Essex had gotten to the mansion earlier that night. He and Laura had been given a room by Mrs. Munroe, and the three had a preliminary interview scheduled for the morning. The woman being polite enough to offer the two a bed and some time to sleep in consideration of the hour at which the arrived.
Laura had immediately gone off somewhere and Nathaniel hadn't particularly been worried or cared. The child could handle herself on the school grounds.
But the doctor found himself being woken to the sounds of explosions and gunfire and basically what appeared to be a war zone. He fell out of bed and used it as cover as his door was kicked open and the intruders didn't bother looking for a target before firing a spread across the room.