Sherlock (Jonny Lee Miller) and Joan (Lucy Liu) will be investigating the death of a self-proclaimed superhero in the upcoming episode of the CBS series "Elementary."

In "You've Got Me, Who's Got You?" TV Guide reports that a man who sees himself as the city's very own crime fighter will get more than what he has bargained for. One night when he goes out sporting his comic book superhero costume, someone will end up killing him. Sherlock and Joan will have to unmask the vigilante, know his true identity, and search for his murderer. They will have to find out who is "strong" enough to kill a "crusader."

Meanwhile, Morland (John Noble) is at it again, pursuing Joan for selfish reasons. This time, he wants her to do him "a business-related favor." To sweeten the deal, the older man will give a huge donation to Joan's most preferred charity. Morland hopes that she will be more amenable and likely to agree if she gets something out of the deal for a change. Will Joan do it? What kind of scheme is Morland hatching this time?

Last episode, Sherlock and Joan investigated a case involving the brother of Henry (Tom Everett Scott), one of Morland's associates. An eyewitness said that the victim died after being pursued to death in the woods by a glowing animal resembling a huge wolf. He was able to escape it, though, by jumping into the road. That was where he met his death when a truck hit him.

The dead man was very wealthy and prior to his demise, he was deep into tech start-up business. Henry said that his brother knew every nook and cranny of that forest. He also shared that there were many people who wanted the other man dead because of his work with Baskerville Genetics. When Sherlock and Joan visited the lab, they found out that it housed a huge hound that indeed glows in the dark.

The dog, however, was a dead end. It turned out that the one they were looking for was a robotic kind. The culprit also sent it to pursue Henry, hoping to kill him as well. With his older brother dead, Henry stood to inherit the Baskerville money. The killer was a cousin who wanted her share of the family fortune.

"Elementary" season 4 episode 17 airs on Sunday, March 20, at 10 p.m. EST on CBS.