Benedict Cumberbatch Sherlock Actor Martin Freeman Watson Actor Rupert Graves DI Lestrade Actor Una Stubbs Mrs. Hudson Actor Louise Brealey Molly Hooper Actor Andrew Scott Moriarty Actor Lara Pulver Irene Adler Guest Star Danny Webb DI Carter Guest Star Andrew Havill The Equerry Guest Star Todd Boyce Neilson Guest Star Oona Chaplin Jeanette Guest Star Nathan Harmer Phil Guest Star Rosalind Halstead Kate Guest Star Peter Pedrero Archer Guest Star Luke Newberry Young Police Guest Star Paul McGuigan Director Steven Moffat Writer Mark Gatiss Writer, Executive Producer Beryl Vertue Executive Producer