With a big grin the Doctor strode into the auxillary control room, threw his scarf over his shoulder and said, "Do you know something Romana?"
Romanadvoratrelundar waited with a resigned look on her face, knowing no response was required.
"I have come to wonder why we're not permitted to visit early Gallifrey" - he paused briefly before cracking another smile - "actually, I've always wondered that. Today I've decided it might be important enough to find out."
Romana sighed. "The Key to Time, Doctor? Isn't that more important than satisfying academic curiosity?"
"Not in this case. I think it's all going to come nicely together." And with that, the Doctor started the TARDIS on its next journey.
"Where are we, Doctor?"
"The temporal protection around Gallifrey is difficult to bypass - but I'm clever, you see. We've gone back to shortly after the Big Bang and we're going to hang about for a while until Gallifrey forms. We have to wait about two billion years or so... but that's the beauty of being a Time Lord. Rather than travel directly there and hit the Temporal Exclusion Barrier, I'm just going to slow down time within the TARDIS and we'll wait it out!"
From outside, the lights of the TARDIS appeared to dim as they red-shifted towards invisibility. And time began to pass unnoticed.
And then there was light! A pair of orange dwarf stars formed from a collapsing cloud and soon Gallifrey had coalesed from the dust ring. Yet more time passed.
"And we're here, Romana! A 2.3 billion year nap is quite refreshing, don't you think?"
"Yes, Doctor. But what do we do now? What are you looking for?"
"We're going to perform a Temporal Skip, skittering into the future by hundreds of years with each 'skit'. When we see the Sisters of Karn arrive... we'll jump back a bit and find out who founded Gallifrey!"
With practiced ease and an air of arrogance, the Doctor operated the console. The TARDIS strained, but the Temporal Skip worked. "Doctor, stop! Look at the monitor!"
"Well Romana, that was a stroke of luck, we've skipped to the exact point of colonization. Let's have a closer look at that ship."
"We can't possibly materialize on board, Doctor, we could destroy all of Gallifrey's future!"
"We'll have to be really careful then, won't we?" And before Romana could stop him, the Doctor had dematerialized the TARDIS for the short spatial trip.
The outer doors of the TARDIS opened, and the Doctor emerged with uncharacteristic timidness. Then he stopped in his tracks, causing Romana to bump into him.
"What is it, Doctor?"
"I've seen this type of vessel before. In fact, I was on one not too long ago. This is an Earth colony ship, from somewhere 12 billion years from now, Earth calendar year 10 million or so."
"But humans on Earth in the year 10 million didn't have time travel, Doctor. They'd lost it at that point, they were facing extinction and fleeing in Ark ships. So who sent them here?"
"That, Romana, is what we need to find out!"