Holmes and Watson find themselves digging through the dark world of the mob to find a killer when they discover the body of a former assassin. Meanwhile, Watson helps a close friend track down a mystery man who swept her off her feet.

When a beautiful young woman is murdered, Holmes and Watson investigate her ties to a billionaire CEO. Meanwhile, Mycroft makes a case for Sherlock to move back to London.

Holmes’ latest investigation takes him inside a professional dance company when an up-and-coming ballerina is murdered. Meanwhile, Watson embarks on a solo enquiry to find a homeless veteran when his friend alleges he was abducted.

When Watson joins forces with Holmes and Kitty to locate a missing nurse she used to work with, the woman’s trail leads them to another person who has recently disappeared.