I just watched this episode and fangirled a lot, because Barty Crouch Jr. and Barty Crouch are in the same episode! And this time Barty Crouch is the evil one! Harry Potter/Doctor Who crossover. Also, more proof that Britain only has like 10 actors.
Holy crap I didn't know the guy who played Barty Crouch Jr. in Harry Potter is actually the same actor who is the one and only Doctor on Doctor Who holy crap that's awesome. Well that case Harry Potter would be screwed.