The tiny reactions are enough to let him know Sentinel was conscious - and more importantly, able to listen. After having spent a week with the Prime's unconscious body, he was rather finely aware of when he'd managed to slip in and out of their world.

Megatron turns his attention to the pieced together mess left of the Autobot's abdomen, his hands resting at his side of the berth.

"Red Alert certainly did a good job of putting you back together. But even doctors can only work with the tools and pieces they're given, can't they?"

He looks at the empty area where the Prime's tcog should be.