As The Doctor and Rose slowly crawl through the dark ventilation shafts, the only light seeping through the grids on the bottom of the vents, it was very dusty and Rose found it hard trying not to sneeze. The Doctor stopped abruptly in his tracks and Rose crashed into the back of him,

"Why you stopped?" she hissed

"There below us" The Doctor whispered pressing his ear to the vent floor

"That's a bit harsh… I know there only crew but…"

"Not like that. There right underneath us" he hissed pointing at the vent floor

"So. Were just going to stop here?"

"pretty much" The Doctor said sitting up and leaned against the side of the vent, his head at a 90 degree angle and his knees pulled up to his chest so he could fit in the small space.

Rose pressed her ear on the cold floor of the air vent; she heard faint mumbling of what to her seemed like two crew members Rose could only make out for words.

"The Earth Shift"

Rose listened intently to there conversation, but to no effect. She had never heard of the Earth Shift before and never heard The Doctor mention it either. Rose then heard a third person screaming and shouting and she could make out every word they were saying.

"The Trespassers Have Escaped!"

Rose jolted her head up, the look of alarm on her face,

"What's the matter?" The Doctor asked

"I think they have realised we've…" but before Rose could finish her sentence an alarm rang through the ship, it echoed down the vents, The Doctor grabbed Rose by the wrist

"We've got to get out the vent" he shouted to her over the noise and pulled her down the vent. They crawled as fast as they could, making sharp lefts and rights, not knowing where it would lead them. As they crawled they could slowly see the end of the vents with a weir meshed grid in front of them, they both pushed and pulled it but no luck,

"Stay back" The Doctor ordered Rose and he kicked down the grid and it landed with a clatter on the floor, The Doctor slid out and landed cat like on the floor.

"We have to find our way back to the TARDIS" He said as Rose jumped into his arms and helping her down from the vent "But first we have to work out where we are" he said glancing around the very small room, a signal light bulb over his head was the only light, it seemed like they were trapped inside a box. The Doctor padded his hands up the wall to find a leaver/ handle or something.

"Doctor. Are we in a cupboard?" Rose asked

"Don't be silly Rose" The Doctor chuckled "what makes you say that?" There was a clicking sound behind him followed by the squeak of a rusty hinge. The Doctor trued to see Rose standing by an open door with a smirk on her face,

"All right you win, just because I didn't see the door first" The Doctor said sulkily as he walked past her

"Thank you" she smiled and followed him out the room. The emerged into yet another corridor like the same as al the other only this time it was a lot darker, red bulbs hung above there heads giving the place an eerie crimson feel to it. The same pipes and cables ran down the walls, but unlike the other corridors air lock type doors littered the walls and it was very humid.

"Where are we?" Rose asked

The Doctor pulled out his thick rimmed glasses and examined a pressure gauge on one of the pipes "I think were close to the ships boilers and generators, which would explain why its so hot" The Doctor said

Rose glanced up and down the corridor, "Which way?"

The Doctor took of his glasses, folded them up and placed them into his pocket

"With my calculations, if the boiler and generators are that way" he pointed past Rose and down the corridor "Then we need to go this way" he said walking away from Rose. But something in the pit of her stomach said that this place wasn't good

"Come On!" The Doctor called over his shoulder to her, she scrambled up the hall to catch up with him.

After they came to another air lock door, they pushed it open slightly to see if the cost was clear, they had come out into yet another corridor like identical to all the other corridors on the ship, except it was a lot brighter than the last. In front of the door was a sign post. To the left was Hall 14 and The Brig to the right leading up a flight of stairs was the Observation Deck and Captains Office.

"Now which way" Rose hissed

The Doctor stepped out the door way followed by Rose and he examined the sign closely "Well. If we landed on the Observation Deck the sensible route would be to turn right"

"Good thing you not sensible then" Rose smirked

"Yeah" The Doctor beamed from ear to ear "Come on lets go find out where my Sonic Screwdriver is" He took her by the hand and lead her to the left away from the sign post. But unannounced to them the door they had just walked out had large red letters painted on which read 'Quarantine.'

As they briskly walked up the hall hand in hand they didn't realise there every move was being watched. A man who sat in a leather chair in a darkened room over looking thousands TV monitors leaned forward, A camera zoomed in on Rose's face

"Bring them to me" he asked

The security guard that stood next to him nodded "yes captain" and he hurried out the room.

Rose shuddered

"What's up?" The Doctor asked

"You ever get that feeling your being watched?" she said looking over her shoulder but unknown to her she was looking directly into the camera.

"Narr. Just you imagin… Hold on" The Doctor froze with a look of awareness "Do you hear that?"

Rose craned her neck up to see if she could hear anything, she shook her head "nope"

"Exactly… The alarms stopped"

Rose looked up at The Doctor with a worried look, The Doctor tugged at her hand and they carried on down the hall.

"FREEZE!" a male's voice screamed behind them

The Doctor and Rose slowly raised there hands and turned around to see what looked like an army of security all with guns pointing at them.

"Hello again" the Doctor smiled.

The one guard stepped forward "The Captain wants to see you two right now"