FFGWHF20 The Enemy Within Supplement By Fantasy Flight Games Warhammer Fantasy RPG Supplement The Enemy Within explores classic themes of corruption and betrayal throughout a massive campaign that can take characters all the way from their first sessions through their third character ranks. The truly adventurous can extend the story into truly epic terrain with an optional epilogue and the rules from Heros Call. It is one thing to face your foe in the field of battle, but can you defeat The Enemy Within?