The TARDIS doors were thrown open dramatically, which the TARDIS probably didn't appropriate, and the five passengers stepped out. For a couple minutes, nothing was said, and the room was looked around in with faces ranging from confusion to awe.
If you've ever seen a control room, this is sort of what it look like, except more... cave-like, and without all the switches and levers and buttons. It's like if someone took a cave and replaced the rocks with rock copycats with multicoloured lights, usually red, green, and blue, all over them, blinking at random intervals. They were all over the place, the walls, the ceiling, even though floor, but, even with them, the room would have almost been pitch black if not for the light of the TARDIS.
John stuck a curious hand out, but the Doctor caught it. John started, giving the Doctor a confused look, but the Doctor wasn't looking at him.
"Don't touch them," the Doctor warned quietly. He let go of John's hand and slowly took out his sonic screwdriver. Bleeping it around, he quickly frowned.
"They're motion sensors," Sherlock guessed, glaring around.
"Close," the Doctor muttered. He brought the sonic screwdriver closer to his ear, listening closely, and then frowned. "No, that can't be..."
"What?" Amy demanded. "Doctor, what can't be?"
"Well, I-I think we're in..." the Doctor gulped. "We're in O.C.T.A.V.I.A's brain?"
"...What?" Rory asked. "How can we be inside her... brain? Did we shrink?"
"No, her actually brain," the Doctor huffed. "The person we met, and keep seeing, is just the interface. It's just... Here, it's just like the geegle search bar."
"Geegle?" John repeated, confused.
"That search bar isn't actually Guugle-," the Doctor continued.
"Gu-gu- what?" Amy asked.
"But it's where you talk to Goioigle," the Doctor finished. "This right here, this is the REAL O.C.T.A.V.I.A."
"...He's messing with us, right?" John asked Amy after a moments silence.
Amy was glaring irritably. "Definitely."
The Doctor clapped his hands. "Whatever, whatever! The TARDIS sent us here for a reason. C'mon, humans! Look around!"
The occupants stepped into the room, looking in all directions, which basically looked like the direction they had been looking in previously.
"Do you think O.C.T.A.V.I.A knows we're here, Doctor?" John whispered. The Doctor nodded and started pointing his screwdriver around, making it do it's familiar bleeping.
"I would be surprised if she didn't," he answered, and as if on cue, a brilliant white light filled the room, emitting from the one person they knew to be O.C.T.A.V.I.A.
"Doctor," the hologram greeted. "Amy, Rory, Sherlock, Watson."
"O.C.T.A.V.I.A," the Doctor replied. "Hope you don't mind us poking around a bit?"
O.C.T.A.V.I.A tilted her head. "I would rather you got on with helping me escape, Doctor."
"Oh?" he asked. He dropped the sonic screwdriver, and the bleeping disappeared. The Doctor then gave O.C.T.A.V.IA. his full attention.
"Doctor, I have nothing to hide," O.C.T.A.V.I.A pleaded. "All you will find is my desperation to get out, and you knew of this already. Please, Doctor, I'm on a time limit."
"A time limit?" the Doctor repeated, his eyes widening. "That's new..."
O.C.T.A.V.I.A hung her head in shame. "I did not think it to be important, Doctor. But I give you my word that I am."
"Can you tell us more about this time limit?" the Doctor requested. O.C.T.A.V.I.A shook her head.
"No, Doctor, I cannot."
"Well, how much time do you have then?" the Doctor asked. O.C.T.A.V.I.A shook her head again.
"No," she whispered. The Doctor winced when her voice cracked. He knelt by her.
"It's okay," he told her kindly. "We're going."
"Thank you," she mumbled. The Doctor nodded at her, and then stood up.
"Well, gang," he announced. "Come on, lot's off work to do."
Exchanging glances, the humans followed the Doctor into the TARDIS, which the Doctor promptly started up.
"So we didn't learn anything from that?" Amy sighed, standing next to the Doctor.
The Doctor smiled mischievously. "Not exactly," he told her. He held up his sonic screwdriver.