Sherlock faces his biggest challenge of all – delivering a Best Man’s speech on John’s wedding day. But all isn't quite as it seems. Mortal danger stalks the reception - and someone might not make it to the happy couple's first dance. Sherlock must thank the bridesmaids, solve the case and stop a killer.
"Sherlock III: The Sign of Three" on Masterpiece Mystery! airs on Sunday, January 26th at 9:00 pm.