Clara woke up in what appeared to be a room in an abandoned laboratory. She looked around.

"Doctor...Doctor?" she said as she got up, but there was no answer.

Nearby, a cracked computer screen flashed as it was almost out of power. Clara walked over to the computer.

"Where am I?" she wondered.

"Let's see if you know," she said as she began pressing buttons on the computer. Suddenly a picture of the leaning tower of pisa appeared on the computer screen.

"The Leaning Tower of Pisa? Well let's try a different button."

On the screen appeared a microphone, under the microphone it said press enter to activate voice recognition.

"Voice recognition? Well ok"

Clara pressed 'Enter' and then began to speak.

"Hello, can you tell me where I am?"

"Thank you for using voice recognition," the voice said. "You are in Laboratory X."

"How can I be in a laboratory? I was in a tunnel," she said confused.

"You are in Laboratory X," the voice repeated.

"Ok, tell me something else. What year is it?" Clara asked.

"The year is 1178."

"What! But how? There aren't computers in 1178."

"I'm sorry, I don't understand, 'What! But how? There aren't computers in 1178.' Try asking a different question."

"How did I get here?" Clara asked.

"Unknown," the voice answered.

"Fine, if you won't give me any useful answers I will just have to find my way out." Clara looked around and spotted the door, she ran over and tried to open it, but it was locked with a combination. She went back to the computer and asked.

"What's the combination for the door?"

"What door would you like the combination for?"

"This door, the door to Laboratory X!"

"Security clearance 5 is required, please log in to receive the answer. "

Clara sighed in frustration.

---------------------

The Doctor woke up and immediately stood up. He walked toward the door, but it was locked with a combination. He noticed the door had "B5" printed on it. He then walked over to a computer in the room, the screen broken and flashing. The Doctor scanned the keyboard with his sonic screwdriver. The screen quickly showed a photo of the Leaning Tower of Pisa and then immediately switched over to the voice recognition screen. The Doctor pressed the 'Enter' button.

"Thank you for using voice recognition. I am here to answer questions."

"How many life forms are here?" the Doctor asked.

"You are the only life form in this laboratory," the voice answered.

The Doctor used his sonic screwdriver on the screen and began typing on the keyboard.

In her location, Clara attempted to access different parts of the computer's software, and each time, it displayed the message, 'Security clearance 5 is required to access this information'. Suddenly, a message popped up on the screen. It read, "Clara, please reply if you got this. -The Doctor".

Clara clicked on the message and typed the response message, "got it. -Clara".

Clara's message appeared on the Doctor's computer screen. The Doctor used his sonic screwdriver on the computer screen again and accessed voice recognition.

"Clara, can you hear me?" the Doctor asked through the voice recognition.

The Doctor's voice came through Clara's computer, partially muffled.

"Doctor, is that you?!" Clara asked.

Upon hearing Clara's voice coming through to the computer, the Doctor used the screwdriver on the computer and then spoke again.

"Clara, can you hear me?" he asked.

Through Clara's computer, the Doctor's voice came through more clearly.

"Yes! Yes, I can hear you," she answered.

The Doctor accessed certain parts of the computer's software as he responded, "Clara, where are you?"

"I don't know," Clara answered. "The voice recognition keeps telling me I'm in Laboratory X. How are you talking to me anyway?"

"I hacked the voice recognition system. Clara, if there's a door where you are, does it have anything written on it?"

Clara turned around and noticed "B5" written on the door.

"It has B5 written on it," she answered. "Where are you anyway?"

"Same location, different dimension."

"If you are in a different dimension, then how can you be talking to me?"

"It's the same computer Clara, I've hacked into this one and made it project my voice, and it did the same thing to that one." The Doctor explained as he began scanning the rest of the room with his sonic screwdriver.

"If we're in the same room then how do we get to each other?" Asked Clara.

"I we have to find the dimensional shifter, if I can disable it than we should be in the same dimension again."

"Right.....how do we do that?"

"Well I've just scanned the room and it's not in here, so I'm going to try to open the door then we are both going to have to go out and look for it."

"How do I know when I find it Doctor, what does it look like?"

"Well I don't know maybe a switch, or a panel, or something that says dimensional shifter on it." As the Doctor was speaking, he triggered the lock mechanism and the door slid open.

"Alright there's two hallways I'll go right you go left, then I'll come back and go left again just to make sure you haven't missed anything."

"Got it, I'll come back here if I find anything." Clara started down the hallway, it was well lit and very clean which surprised her because it was a seemingly abandoned building. As she walked she examined the walls, but they were all perfectly smooth, no switches, or panels.