Regeneration K-9 is the first episode of series one of Doctor Who:Infinity. It introduces Luke Smith and K-9 as the tenth Doctor's new companions.
Part One - Regeneration
The Doctor entered his TARDIS heading for his next destination. Then the Doctor thought why don't I ask Luke for help. I could prevent my regeneration - I could survive. He went back out of the TARDIS, and collapsed to the floor. Sarah Jane ran over to help, followed by Luke.
"He's regenerating. Luke, any ideas?" ask Sarah Jane, bent over the Doctor
"What's he dying from? K-9 can tell us!" Luke ran into his house, glad the Doctor was back. K-9 was happy to help and they went down back to the Doctor. This would be exciting, having the Doctor back.
Inside the Doctor's head he was having a dream. He saw the future. Men with knives. The Daleks. The Daleks were attacking fast. Cybermen joined them. Then Luke and K-9 arrived with somethinga way to fight back. And then he woke back up.
"K-9! You took all the radiation. Your gonna shut down!" excalimed Luke, not noticing the Doctor wake up.
"Affirmative! But masters primary functions are re-establishing. Mission accomplished!" said K-9, and Luke and Sarah Jane saw the Doctor grinning.
And then K-9 erupted in light, and then it returned and he was new. A new K-9. Regeneration K-9.