Watson tries to engage Kitty's help with trailing a suspect, but Kitty rebuffs her request. Meanwhile, one of Sherlock's math experts, Harlan Emple, finds more than he expected when he stumbled upon a dead body during a math puzzle competition. Sherlock quickly deduces that the game is not what it seems. After you solve the math riddle, you receive GPS coordinates to the next clue. But instead of finding the next riddle, two contestants have been tortured and shot instead. Some of the contestants gather to identify the killer whom they believe is an annoymous blogger named Mo Shellshocker. Paul, the leader of the group, says Mo had a heated online argument with both of the victims. Harlan declines to help, which doesn't surprise Sherlock because he knows Harlan is Mo. But Harlan is not the killer. He created the Mo persona as a way to emulate Sherlock. So who is the killer? And what does he want with the mathematicians? Joan's concerns about Kitty grow after learning more about her background. She insists that Sherlock get Kitty the professional help she needs to recover and heal. Will Kitty finally accept help? Find out the answers when you watch Elmentary Online via TV Fanatic.