Watch Sherlock Online - Full Episodes

"Sherlock" is a detective show based on the works of Sir Arthur Conan Doyle. The show is a modern-day update of the Sherlock Holmes stories and first aired on BBC One and BBC HD in the summer of 2010; the show is aired on PBS stations in the United States. The show has run for two seasons, with a third scheduled to begin production in early 2013. Each season has featured three 90-minute episodes.

The show was created by Steven Moffat and Mark Gatiss, who are also the executive producers. Moffat and Gatiss also write one episode each per season, as does Steve Thompson. Each episode is based on one of the original Sherlock Holmes stories. Although each episode features many similarities to the original story, the details of the plot and the ending are often changed, keeping even devoted fans of the original stories guessing.

The title role of Sherlock Holmes is played by Benedict Cumberbatch, whose other film credits include "Hawking,""Amazing Grace," and "Atonement." His work in "Atonement" drew the attention of Moffat and Gatiss, who targeted Cumberbatch for the role. Cumberbatch has drawn praise for his portrayal of the cold and calculating Holmes; his performance caused the writers to change the character for the second series to more effectively make use of his skills.

Dr. Watson, Holmes' faithful companion, is played by Martin Freeman. His other credits include "The Office,""The Hitchhiker's Guide to the Galaxy," and "Love Actually." In this modern update, Watson is a veteran from the Afghanistan conflict who struggles to adapt to life away from combat. The friendship between Watson and Holmes is a recurring theme throughout the show. Freeman won the BAFTA award for Best Supporting Actor for his work as Watson.

Andrew Scott plays Jim Moriarty, Holmes' archenemy. Scott has also appeared in "Lennon Naked,""Dead Bodies," and "My Life in Film." In casting Scott, the creators of Sherlock stated that they wanted to break the mold of Moriarty as a dull and posh villain. Scott has been praised for his portrayal of the manic and psychotic Moriarty and won the 2012 BAFTA award for Best Supporting Actor for his portrayal of Moriarty.

Rounding out the cast are Una Stubbs as Mrs. Hudson, the landlady of 221B Baker Street; Rupert Graves as Detective Inspector Greg Lestrade; and series co-creator Mark Gatiss as Mycroft Holmes, Sherlock's well-connected older brother.