The Doctor kissed Jack back and closed his eyes, he had tears in his eyes, he had been scared for them. "Yes.... I know, the guy on the phone said something about her, Though I have a feeling I know who it is, And I had forgotten about them, but yes talk later,"
He headed back to the SUV. He didn't want to talk about the Master too much till they got back, though he knew Jack knew who the Master was. 
The Doctor was quiet when they got back, he was thinking, he was also still rather tired and slept when Jack drove them back, He got out of the SUV and looked around. If the Master was back, he still couldn't kill him.