If you are looking for an interesting guide to , the most prominent and high-stakes "M" episode in television belongs to the crime drama Elementary .

Sherlock reveals to Joan Watson that he believes "M" is responsible for the death of Irene Adler , the only woman he ever loved. This loss is what originally sent him spiraling into the drug addiction that brought him to New York.

In this episode, a serial killer from Sherlock's past in London appears to have followed him to New York.

After Sherlock tracks down and captures the man he believes is M—a British thug named Sebastian Moran (played by Vinnie Jones)—he discovers that Moran could not have killed Irene.

The episode moves away from the "case of the week" format and firmly establishes the series' overarching mythology.