Could we ever see a Dr Who story by Golden Compass author Philip Pullman?
Newsround asked if he would consider writing an episode of the sci fi show. And he said that writing a story for The Doctor "sounds like enormous fun".
He said: "This recent Doctor Who, since Russell T Davies came back and started having a hand in it, has been wonderful.
"I've really enjoyed it. David Tennant is terrific. Billie Piper was wonderful as Rose," he added.
Pullman also talked about the end of series two of Doctor Who - when Billie was left in a parallel world - and how similar some people say it is to his own Dark Materials series.
"I was flattered by it," Pullman said.
"That's how stories work. Stories are made out of other stories. I borrowed things for His Dark Materials. He [Russell T Davies] took my ending and twisted it to fit his story. That's fine."
Rowling for Doctor Who too?
Anthony Horowitz wants to write for Doctor Who
Since Dr Who returned many fans have hoped that their favourite children's authors might write a story.
When Russell T Davies was planning the first series he asked Harry Potter creator JK Rowling if she would write an episode.
But the author, who was working on the sixth Potter book at the time, said no.
More recently Stormbreaker writer Antony Horowitz has said that he had approached the BBC and asked if he could write an episode.