The fourth season of "Sherlock" will return to BBC1 on New Year's Day 2017. This season will still have three episodes, with the titles being: Episode 1: The Six Thatchers: written by Mark Gatiss and directed by Rachel Talalay; Episode 2: The Lying Detective: written by Steven Moffat and directed by Nick Hurran; Episode 3: The Final Problem: written by Mark Gatiss and Steven Moffat, directed by Ben Caron.