Benedict Cumberbatch is the latest in a string of A-Listers who has been invited to join the iconic characters on Sesame Street.
However they're not making it easy for him as they test him with a problem that even Sherlock might struggle with and in the end Cumberbatch has to call on Count Von Count for help!
The rogue who piles the pressure on Cumberbatch isn't quite Moriarty, or at least not as we know him, but rather his alter-ego Murray-arty.
Watch the actor in action here:
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