"Afternoon, sir," the armed security guard says to dad as we roll toa stop in front of the gates of Baskerville."If you could turn the engine off." Dad hands over his I.D. pass and switches the car off. "Thank you." As he goes over to the gate room to swipe the car, other soldiers and a dog handler with an Alsatian steps forward to check the car over from the outside.

"I need to see Major Barrymore as soon as we get inside," dad says quietly to John.

"Right."

"Which means you'll have to start the search for the hound," he continues.

"Okay."

"In the labs; Stapleton's first." The guard brings back the I.D. card and hands it over. "Could be dangerous," he finishes and I smile slightly, thinking back to our first case with John where those same three words motivated him to travel halfway across London to let dad use his phone. The gate slides open and dad starts the car again and drives into the base.

A shortwhile later, John splits away from us and heads in the direction of the labs while Dad, Beth and I walk towards Major Barrymore's office. It doesn't take us long to find it and dad knocks on the door before opening it slowly.

"You don't need to explain," Barrymore says, almost immediately. "I've heard."

"So you'll let us have access to the base?" Dad confirms.

"Oh, you know I'd love to," Barrymore replies snarkily, turning away from his computer. "I'dloveto give you unlimited access to this place. Why not?!"

"It's a simple enough request, Major," I reply.

"Giving two teenage girls complete and unlimited access to a hightly secure military base? I've never heard of anything so bizarre."

"You're to giveus twenty-four hours. It's what I've ..." he pauses momentarily as he thinks back to his argument with Mycroft earlier, "... negotiated."

"Not a second more," theMajor says sternly."I may have to comply with this order but I don't have to like it." He swings back around to his computer and we start to file out the office. "Idon't know what you expect to find here anyway."

"Perhaps the truth," dad says and Barrymore looks back around.

"About what? Oh, I see. The big coat should have told me." I frown andthe Major elaborates. "You're one of the conspiracy lot, aren't you?" He grins and I roll my eyes. "Well, then, go ahead, seek them out: the monsters, the death rays, the aliens."

"Have you got any of those?" I ask nonchalantly and it's Barrymore's turn to roll his eyes. "Oh, just wondering."

"A couple," he says, leaning forward secretively. "Crash landed here in the sixties." His tone changes to sarcasim. "We call them Abbott and Costello, but wait - you're too young to understand that reference." I make a mental note to look them up later as Barrymore straightens up and turns back to his computer. "Good luck, Mr Holmes."

I follow dad out of the office and we stop in the corridor outside. The colonel who showed dad and John around the day before approaches us, a look of uncertainty on his face.

"The Major shouldn't know I'm doing this," he says. "But your brother said you may be able to help, Mr Holmes."

"Bit busy right now. Whatever it is can wait, especially if it was referred by my brother."

"Wait," I say and dad looks around. "I can do it. Beth and I can do this one together." He looks to Beth who shrugs, slightly nervous at the prospect of doing her own case.

"Okay," dad says at last. "Don't be too long. I'll be in the control room when you're done." I nod and turn to the colonel.

"Lead the way, colonel." He nods sharply and spins around on his heel, leading us towards the lift at the end of the corridor as dad watches us go. "So what's the issue?"

"After you left yesterday we found a few more people downstairs," he explains as we step into the lift. "The problem is, the room we found them was locked from the outside. They were on the inside."

"Did theybreak in?" Beth asks, frowning and I smile at her initiative. The doors open and he leads us back out and down another set of passageways.

"There was no sign of a break in," the Colonel shakes his head, "but they didn't come through the front door either." He stops in front of a door. "They just appeared." He opens up the viewing hatch for us to look through. Stood justthe othersideofthe door is a youngish man with what would seem to be his wife watching from behind, her arms crossed as she narrows her eyes at us. In the corner of the room, the eyes of another man rise slightly to meet mine.

"Hello Doctor," I say with a facade of confidence. This isn't the Doctor I remember, but from what I remember from John he has the capability to change his face. Although this man looks young, his eyes have seen much more than it would first appear.

"Hello Sophie!" the Doctor responds, jumping forward and standing in front of the hatch. "Knew you'd come along."

"No you didn't," I scoff. "You had no idea we would be here." Beth, who had been listening from behind steps forward to my side.

"Did you say Doctor?" she asks, frowning and I grin. She looks through the hatch and sees the Doctor for herself.

"Let me guess, you're afan," I say. Becoming aware that the Colonel is still stood right beside me, I change direction. "Beth I would like to formally introduce Doctor John Smith of the Institute for Genetics. He's been helping us with thiscase." I look hard at the Doctor who smiles and joins in.

"When I heard about this placeI couldn't resist a look," he says. I nod and turn back to the Colonel.

"There's obviously been another mistake, Colonel. The Doctor is prone to getting into trouble. He must have thought this was a lab and the door locked behind him. There's no other explanation for it."

"So you know him?" the Colonel confirms hesitantly.

"Absolutely. Now if you could release them, it would be much appreciated." Noticing Beth still has her mouth agape, I nudge her slightly and it shuts quickly. The Colonel nods and keys a code into the key pad beside the door and we watch it open. "Thank you. Now I believe we can show ourselves out. I have somewhere I need to be."

"Of course, Ma'am," he replies and gives us some breathing space as we make our way towards the lift.

"So is there a reason why you managed to get locked inside a high-security military base in Dartmoor?" I ask but the Doctor is interrupted before he can answer.

"I'm sorry, am I missing something?" The woman asks, striding up beside us. Her accent is Scottish, but her mannerisms suggest she was raised away from her home. "Who the hell are you."

"Amy, Rory," the Doctor says, spinning around and grinning, "This is Sophia Holmes, daughter of Sherlock Holmes."

"Okay," the male, Rory, replies to Amy. "Did he just say 'Sherlock Holmes'? Did I hear that?"

"Yeah," Amy responds slowing down. "I think he did. How?"

"Parallel universe," I explains. "Sherlock and I exist but the books that feature our exploits do not." I exchange a look with the Doctor before continuing. "Or as the Doctor would call it, 'spacey-wacey'. Much easier for you to understand, I expect." Amy and Rory exchange looks and Beth nudges me.

"Rude," she whispers and I roll my eyes.

"Now if you're quite finished, I need to get back to the case,"I finish. The Doctor drops behind.

"If you want to avoid being called stupid, don't say anything," I hear him say to his companions. "Especially you, Rory."

"Now back to my original question," I say as the lift doors open. We step outside and stand to the side. "Why are you here?"

"You said Dartmoor, yes?" The Doctor asks and I nod. "So Hounds of Baskerville?"

"So we've done this in the books as well?" I ask.

"You and Sherlock didn't go though, John was sent down on his own."

"That nearly happened," I admit. "So you're here because of the Hound?"

"Don't know," the Doctor replies. "Kinda slipped through the worlds again. Cracks in space and time are opening up everywhere and parts of worlds are seeping through. Have you seen any?"

"Can't say I have," I respond and Beth shakes her head.

"Where are we up to in the TV show?" The Doctor asks Beth, who looks stunned at finally being addressed.

"Past where you are now, I would guess," Beth says slowly. "Cracks in time and space kinda runs all the way through but I'm further along than that. I don't want to give anything away."

"Course not," The Doctor grins. "Spoilers." I shake my head.

"We need to get back to Sherlock," I say and the Doctor nods in understanding. "So I suppose this is bye for now." He smiles.

"I don't believe in goodbyes," he replies and I return the smile. I turn to walk away but remember something.

"Doctor." He turns back around and I feel the eyes of him and his companions on me. "That Christmas present - one of the book titles was the Final Problem. What does that mean?"

"Have you read it?" The Doctor asks, narrowing his eyes in concern but I shake my head and he looks relieved. "It's as you would have probably guessed - it's the last book that I could find about Sherlock. I believe it's happening quite soon." I breathe out a shaky breath but nod. "I'll be there, if I can. It's a fixed point and I won't be able to do anything, but I'll be there for you when it happens."

"Thanks," I reply, nodding. "See you then, I guess." His eyes long solemn as he returns the nod and I turn away before the tears start to sting my eyes.