Secret Rooms.
Rose paused and looked around, she knew the TARDIS wanted to lead her somewhere, but was not sure where. She quietly walked passed the doctors room, not wanting to wake him in the middle of the night, she continued and found a door straight in front of her. She decided t find out what was inside.
She took a deep breath and quietly pushed the door ajar. Finding that nothing was going to jump out at her, she fully opened it and saw a beautiful room. She realised that the TARDIS knew that she had been looking for a place to be alone, and had shown her a place that the doctor didn't know about.
The doctor turned around and tried again "Can you PLEASE tell me where she is? I really want to talk to her." He cursed under his breath. The TARDIS just laughed and continued to tell him that Rose wanted to be alone for a while.
"I know, but it's an emergency" he argued, knowing full well that if the TARDIS didn't want Rose to be found, he wouldn't be able to find her. He cursed again, thinking of all the unexplored areas inside his ship. He slowly walked down the hall, towards Roses room, and sat on her bed, ready to wait until she came out of where she was hiding.
Rose stretched, and slowly opened the door to her room. She dumped a book on her dresser and turned in surprise to see her companion studying her from her bed.
"Where have you been" he asked quietly, hoping she would tell him.
"Oh, around" she replied, waving her hand vaguely. She knew that the room she had been in, The doctor didn't know about and she intended to keep it that way.
"Fine" he growled, "it's nice to known that even the TARDIS has teamed up against me, and seeing that I can't torture her to find out, I'll have to torture you!"
With that, he jumped off the bed and chased after a shrieking Rose, intending to tickle her until she told him.