"HOLY CRAP "I knew he looked familiar! Dean Thomas, 20 points to Gryffindor!" The actor is Alfie Enoch who appeared in the Harry Potter films as Dean Thomas. He is in Sherlock season Daaaaayyyuuumm 20 points to Gryffindor indeed.
Exactly how it went down when my friend fell in love with Sherlock. And a different friend didn't love Doctor Who.<----- I usually end up forcing people to try again, because they only watch the first couple episodes of Doctor Who.