This story takes place soon after Ageless Lunica
The TARDIS materialised on Telos. Inside, The Doctor was busy running around the console, flicking switches in what seemed to be a dance routine, before flourishing and flicking the exterior moniter switch, after which the moniter showed an image of what looked like a frozen wasteland.
"What are we doing back on Telos, Doctor?" asked Peri nervously.
"Well, in the past I made a bit of a pickle. I created a paradox with those Cybermen, but I assumed that since the Universe didn't explode, I must intervene at some point in the future. Those Cybermen should have been on their way to the frozen tombs of Telos to become cyberNeomorphs."
"But the Cybermen on Lunica weren't the same as the ones from Telos. And it's far too early for them."
"No, Peri, this is the time of the great, underground civlisation of the Cryons. You see, Doctor Cranax, a Time Lord, made only three Emergency Exterior Temporal Transportation Devices. One was given to a prophet, who went to Gallilee in Jerusalem, one was given to me and the last was a present to the Cryon Race."
"So you need the Cryons' ETD to send the Cybermen to Telos?"
"Exactly, Peri! Your getting better by the day. Now, off to work we go!"
They walked out onto the surface of Telos, spotting a small cavern near the TARDIS. At the bottom of the cavern was an airlock door, that the Doctor casually opened. He motioned Peri to go inside before him.
"These are Cryons; We have to shut the door behind us." Peri smiled.
End of Part One