The TARDIS doors are flung open. Jack barges in, closely followed by Martha and Mickey.

"Hey, have you guys found a way to make contact ……," Jack breaks off mid-sentence when he sees the Doctor.

The Doctor is rooted to the spot, staring at the console. There are tears pouring down his face.

"What's happened?" Jack queries, turning to Donna for an explanation.

"Rose happened, that's what!" exclaims Donna.

"Rose?" Mickey's ears prick up at her name.

Martha approaches the Doctor, puts a comforting arm around his shoulders and leads him over to the jump seat. He gives her a wan smile.

"Yes, Rose. She has a telepathic link with the TARDIS and was able to contact us," Donna replies. She glances at the Doctor, seeking his permission to tell them the rest of this latest development. He gives her a slight nod of approval. He is still trying to get his head around all that Bad Wolf had told them.

"So there you have it," Donna concludes a few minutes later.

"Wow, trust Rose to save the day," Jack states with glee. "So what's next? Can we help you find a way to get back to the parallel world?"

"I don't think so, Jack," the Doctor speaks up, breaking his silence. "Like Bad Wolf said, two heads are better than one. This is something that only Donna and I can do."

"Well, what are we waiting for, time boy? Let's get to work!" Donna replies, ready for action.

The Doctor gives her a grin and leaps to his feet. "Ok, everyone out. We have a rescue to plan!"

With that, the Doctor ushers a very stunned Jack, Martha and Mickey out of the TARDIS and locks the door behind them.

*********************************************************

"Where are we?" Donna asks the Doctor a few minutes later.

They are standing in the doorway of a rather small room. There are no furnishings at all, just white roundels on the walls and a smooth white floor.

"This is the Zero Room," the Doctor tells her.

"Ah yes, I recognise it from your memories now. But how can this room help us?" Donna gives him a puzzled look.

"I want us to link minds. In order to do this we need total silence and no disruptions. Once I close this door, nothing and no one can get in."

"Ok, let's do this then," Donna nods her agreement.

She moves into the centre of the room and sits cross-legged on the floor. The Doctor follows her, closing the door behind him. She glances behind him. There is no sign of the door, no hinges or door handle, nothing.

"How do we get out again?" she asks in a startled voice.

"The door will reappear once we're finished. Trust me." He gives her a reassuring smile as he moves over to sit opposite her.

Donna gives him a nod and a smile. "How do we do this then?" she asks.

"Just like before. I'm going to look into your mind, but this time you will be able to look into mine as well. We both have the same memories, but you may notice something that I miss, what with your 'extra bit of human' to make you different!" the Doctor teases her.

"Oi, watch it space boy!" Donna exclaims.

"Sorry, sorry. Just trying to put you at ease," the Doctor says, holding his hands up in front of himself in mock surrender.

"Now then," he says, all joking forgotten, "just put your fingers to my temples and I'll do the same to you. We are going to be levitating, but don't worry, we won't fall."

Donna closes her eyes and places her fingers against his temples as instructed. The Doctor mirrors her movements and a moment later she feels herself rising up off the floor.

"Open your mind to me, Donna," the Doctor whispers quietly.

She drops her mental barriers and senses him entering her mind. It feels just like the last time, a warm, calming presence. He 'shows' her how to enter his mind in return. She finds that his mind is totally open to her, nothing is hidden from her. Then again, why would it be? She shares the same memories as him.

The Doctor takes her 'hand' mentally and shows her what sort of information they are looking for. She 'nods' her understanding and starts sifting through his memories, aware that he is doing the same with hers.

All sense of time is irrelevant in the Zero Room. They could have been there for hours or days. They keep searching, looking for that elusive memory that will give them the solution to travelling safely across parallel universes.

Donna finds a thread of a memory that seems promising. She follows the thread, getting more excited the further she goes. When she reaches the end, she knows that she has found what they are looking for. She 'grabs' the Doctor's 'hand' and shows him what she has found.

"Donna, brilliant!" the Doctor shouts, breaking contact with her mind. "I would never have thought of that, not in a million years!"

She opens her eyes and notices that they are sitting on the floor again.

The Doctor jumps to his feet, pulling Donna with him. He grabs her up in a big hug, his smile nearly reaching his ears.

"Let's go tell the others what you have found. We also need to get the TARDIS to let Rose know. We'll soon have her back with us!" the Doctor beams.

*********************************************************

"And so all we have to do is recalibrate the extrapolator shielding, add the dimension stabiliser and reprogram the TARDIS's warp engines. Should take a couple of days," the Doctor finishes explaining to Jack, Mickey and Martha.

They are all seated in the conference room.

"It would probably be faster if we had K-9 to help reprogram the TARDIS," Donna offers.

"Great idea," Jack agrees. "I'll get onto Sarah-Jane right now. She's in town at the moment, working on a project for me and I know she has K-9 with her." He heads off in the direction of his office at a run.

"What can I do to help, boss?" Mickey asks, not wanting to be left out of the action.

"I need your help calibrating the dimension stabiliser," the Doctor tells him. He is grateful that Mickey is willing to help him, especially after all they have been through.

"Donna is going to take care of the extrapolator. Martha, can you give her a hand?" the Doctor asks.

"Of course, Doctor. Anything to get Rose home where she belongs," Martha tells him, giving him a wink.

"Ok, boys and girls," Jack says, entering the room. "Sarah-Jane and K-9 will be here first thing in the morning. Let's all get an early night. We have a big day ahead of us tomorrow."

*********************************************************

"Programming complete, Master," K-9 informs the Doctor.

"Good boy, K-9," the Doctor says, giving K-9 a pat on the head.

He looks over to Sarah-Jane, who is sitting on the jump seat. "Thanks for bringing him to help," he says to her quietly.

"My pleasure, Doctor. I just hope you don't blow it this time," she scolds him.

"I won't, believe me!" he assures her. "Besides, I don't want to find out what those consequences are that Bad Wolf mentioned. Somehow I don't think they would be very pleasant."

"You really do love her, don't you, Doctor?" Sarah-Jane asks in a forlorn voice.

"More than anything," the Doctor replies softly.

He notices the tears forming in her eyes and goes over to give her a hug.

"I'm so sorry I left you behind, Sarah-Jane. But it could never have been like this between you and me."

"I know that now," she chokes. "That doesn't stop it from hurting." She starts sobbing in earnest.

The Doctor searches for something to say but fails miserably. He settles for holding her, rubbing his hands up and down her back and making soothing noises.

After a few minutes her sobs turn to sniffles. He offers her a handkerchief, which she takes gratefully.

"You must think I'm a fool," she tells him with a half-hearted smile.

"Never," the Doctor assures her.

"I'm fine now. Sorry about that. Got a bit carried away." She forces a bright smile onto her face. "Let's see how the others are getting on." She hops down from the jump seat and heads for the door.

*********************************************************