Some fans of the BBC drama have been disappointed with the more comedic approach from this third season.
If you're in this more serious camp, you'll be pleased to hear that the finale episode will see the arrival of Benedict Cumberbatch's worst villain yet.
Moffat spoke to Chris Evans on Radio 2 and warned, "We've been lighter this year, we're building to something darker and we're bringing on a cracking villain, Charles Augustus Magnussen."
"He's a mesmerising, chilling villain. It's more of an emotional roller-coaster."
When discussing any future seasons he hinted that there may be one, "assuming we don't just kill them in a horrible bus crash."
With regards to plot holes he explained, "Sometimes we expect the audience to work things out for themselves.
"Sherlock makes the assumption that the audience is clever, but newspapers don't always."
He made no specific reference to the underground station discrepancies, but simply stated, "it is of course, made up."
That's good enough for us!
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