Even with a vast knowledge of how to travel through time and space, Doctor Who showrunner Steven Moffat says he's "actively engaged" in the hunt for the right person to take over his role after he leaves, he told Radio Times.

While his departure isn't imminent, he's beginning to think about his exit from the British sci-fi series -- a veritable institution in the U.K. Head writer and executive producer since 2010, Moffat is giving serious thought to who'd succeed him. It's not an easy decision, he said.

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"Everything is difficult in Doctor Who, including leaving," he said in the interview. "I would never leave it in the lurch because it means too much to me. Yes, it's a problem. Let's not pretend it's not a big problem. But there will be a solution."

Who do you think might be right for the job?