Benedict Cumberbatch's guest starring turn on "Sesame Street" has finally been revealed. And as you may have been able to deduce, the clip is focused on his turn as Sherlock Holmes from PBS' "Sherlock."

The TV/movie star joins the long list of guests who have helped kids learn on the show, from One Direction to Katy Perry and everyone in between. In this clip, Sherlock — er, we mean Cumberbatch — is challenged by "Murray-arty" to figure out whether there are more oranges or apples on a table. While we don't expect this is a mystery worthy of Sherlock's talents, he does enlist the help of Count Von Count to help figure out the "Sign of Four (or is it Three?)."

Even more surprising, the sketch kicks off with a spoiler directly from the very last scene of the last episode of "Sherlock." Murray enters saying, "Did you miss me? Did you miss me?" just like the surprisingly returned Moriarty does in the Series 3 cliffhanger. So yeah, if you don't like spoilers for "Masterpiece Theater," better stop watching "Sesame Street."