As Sherlock fans await the arrival of season 4, co-creator Steven Moffat recently spoke on getting inside the mind of a genius.

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Moffat and co-creator Mark Gatiss adapted their Sherlock series from the Arthur Conan Doyle stories from over 100 years ago. Moffat explained to RadioTimes.com recently just how they write those famous Sherlock (Benedict Cumberbatch) "deductions."

"Doyle told us how to do it. His cleverness was laid out for us 100 years ago. Those deductions are hell," Moffat admitted. "They're very hard to write but as a demonstrated intellectual skill, it's pretty unstoppable. Doyle's first point about detectives was: you can't just say they're clever, they've got to be clever.

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"Every episode we try to have a new cool deduction that makes sense. Now, if you deconstruct most of them, Sherlock has a lucky knack of always guessing right, but let's leave that aside, it's the deductions that make him clever. Very often in the stories we tell of Sherlock are the days he fails or gets too emotional, because the most dramatic tale to tell about a clever man is that being clever isn't enough."

Fans got to see Sherlock and Watson (Martin Freeman) in 19th century garb in the most recent special, Sherlock: The Abominable Bride. This special, which aired on New Year's Day in the United Kingdom and the United States, should tide fans over until season 4.

Season 4 of Sherlock is expected to premiere in 2017.

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