Sherlock fans have something to look forward to: a one-off special, followed by a three-episode fourth season. Were ready to unleash the most shocking and surprising series of Sherlock yet, BBC One writes on Twitter. The only thing is to expect is the unexpected. Sherlocks seasons have come at a fairly slow pace, premiering around two years apart. With the schedule announced today, it sounds as though Sherlock could be on schedule to deliver its next season in 2016 — once again after about a two year break.