The immortal was weak. He closed his eyes and fell asleep. He had been aware about the tapping he had been doing. Jack snored and curled up more. The Doctor was looking at her, his eyes serious. "It is... because the Master is here," He didn't want to kill the other time lord but he needed to stop him. He was sure Rose was going to ask more. Jack had a fever and the Master was trying to take over earth.
He was glad Jack couldn't die at least.