The Sherlock special that aired yesterday topped ratings in the UK with 8.4 million viewers, Deadline reports.
After a hiatus, Sherlock returned to UK television last night with the one-off Sherlock: The Abominable Bride, which was set in the Victorian era rather than the modern twist that differentiates Sherlock from most previous Holmes adaptations.
The episode was the first installment of Sherlock to air on the same day in the United States, although PBS hasn't yet released numbers for the American ratings.
The special also got a limited theatrical release in the UK which will expand to selected theaters worldwide soon.
Sherlock is one of the BBC's biggest hits internationally, with millions of viewers in the U.S., China and other global markets.