British Cabinet Minister David Raffo asks to see the file the British Secret Service MI5 kept on him when he was a student radical in late 1960s Britain. Immediately he receives threatening emails signed by The Joker. The closer he gets to unmasking the identities of the informers who spied on him in the past, the more threatening the emails from The Joker become. He realises there is a traitor in MI5 who is desperate not to be flushed out. The minister's...