Sci-fi and fantasy author Neil Gaiman is ready to write more for Doctor Who.

"If you examine my DNA and you go in deep enough, with a good enough microscope, you're gonna see a TARDIS, with a little light blinking on the top," Gaiman told Digital Spy.

Gaiman has written two episodes, "The Doctor's Wife" in 2011 and "Nightmare in Silver" in 2013, both when Matt Smith played The Doctor. He'd now like to write a script for Jodie Whittaker, the Thirteenth Doctor and the first woman in the role.

"So the idea of writing for Jodie, or for her successor, whoever she/he/they happen to be, is... yeah, it's Doctor Who!" Gaiman said. "You can't say no."

The author said he had planned to write a script for Peter Capaldi, who played the Doctor before Whittaker, but was busy with Good Omens, the Amazon TV series based on his 1990 book, which was co-written with the late Terry Pratchett. Now that filming has wrapped, he's ready to answer the phone.

"Doctor Who's the one call that I will always take," he said. "It's like a drug. It doesn't go out of your system."

Doctor Who will return sometime this fall, with Whittaker in the starring role. Good Omens is scheduled for release sometime in 2019.