Richard not Rupert, Ant....Rupert Brook was a 20th century poet. No he is Moriarty, pretending to an actor, pretending to be Moriarty.
I just found him cliche crazy, trying to do a young Jack Nicholson with none of the menace. I didn't sense his intelligence. Master criminal? I could see him pinching sweets from W H Smith - but nothing more. No - sorry - but Moriarty was a casting mistake.