The whirring and bellowing of the TARDIS echoed throughout the network of caves and caverns, and then a deafening silence. The doors flung open and out burst The Doctor, his gangling companion and her lumbering husband following close behind.
"This is Mars, not the red one, which isn't red, it's brown." announced The Doctor knowingly.
"No, this is caves. Damp, pink caves." replied Amy indignantly.
"Doctor, you did kind of promise Aruba." Rory said.
"Yes, yes, I know but there aren't candy pink caves in Aruba!" The Doctor shouted and he listened as the echoes rang out.
"Sounds like a long a complicated cave network, so I'll say this but I'll doubt you humans will listen" started The Doctor condescendingly,
"DO NOT WANDER OFF!" yet again listening to the echoes.
The Doctor started off towards his left for a reason not apparent to neither Amy nor Rory. But they followed obediently. Then the Doctor started to sprint, without a word he just took of down one of the caves many corridors. After 30 seconds of solid sprinting the Doctor stopped at, what appeared to be a ventilation shaft. He pulled out his trusty sonic screwdriver and proceeded to sonic the vent.
"Doctor, why did you just run off like that?" asked Amy breathlessly.
The Doctor chose to ignore her question and continued with his craft. After a few seconds a hologram popped out from the vent.
"Welcome to mars, population 18,009 and decreasing." blared the hologram in a stereotypically robotic tone. The hologram then disappeared back into the wall.
"Doctor, why did you run? And what did it mean, "decreasing"?" Asked Amy, a hint of panic creeping into her voice.
"Let's just go, this is a bad place and we must leave now!" said the Doctor in a scarily calm voice.
"Where's Rory?" asked the Doctor in a terror filled voice.
Amy looked round and the terror simultaneously crept over the Doctor and his companion. Amy was scared, she didn't know what there was to fear but she knew that anything that scared the Doctor was possibly the most horrific thing to exist. At this point the Doctor ran back to the TARDIS quickly followed by Amy. They leapt through the doors.
"DOCTOR, WE CAN'T JUST LEAVE HIM!" wailed Amy.
"We aren't" said the Doctor running to the back of the TARDIS. He reached a heavy metal door which had a cornucopia of different bolts and locks. After about 5 minutes if frantic key fiddling and under breath swearing the door creaked open. Inside was a armoury of alien weapons. He ran and picked up two large, black rifles which had a greenish hue. He bolted back to Amy and gave her one of the guns.
"This is the most important thing I will tell you ever, what is going on here is one of the most chilling, harrowing things in the universe. If you come shoot everything that moves on site. If you don't want to come I will lock the TARDIS but I want you to keep a gun trained at the door." said the Doctor in the most sincere way he has ever spoke to Amy. His eyes had glazed over momentarily in much the same way a war veteran's does as he recounts stories from his service.
"I'll come." replied Amy. Her curiosity had gotten the better of her fear and she simply had to go.
"Ok." said the Doctor. Putting the TARDIS into a flux loop to protect it from the horrors of what dwelled in the candy pink caves of doom. As Amy and the Doctor stepped out into the darkness they cocked their guns and headed off in search of the missing one of their party.