The Master looked over the Doctor, a bit of a confused look came over his face at the other Time Lord's appearance. That definitely wasn't how he'd last seen him. But the Doctor's words were even more confusing to him. Rassilon? Time Lords? They were long lost in the Time Lock.
"What do you mean Rassilon and the Time Lords? They're in the Time Lock, obviously." For a moment he wondered if the Doctor had cracked, but perhaps it was just a side effect of getting pulled here. "As for where we are, we're in a parallel universe. As Romana told me, a demon pulled us here. A demon who wants to unleash Lucifer upon this world." He studied the Doctor, not daring to move any closer or any further away. At least this Doctor recognized him, but the Master couldn't quite place where he came from. And oh what a treat this would be! He could play with two Doctors! Course that only meant double the trouble when it came down to it, but the Master did love to antagonize the Doctor.