Hidden Agenda is an expansion to The Resistance that has 3 different modules:
Assassin Module: Ever since we announced The Resistance: Avalon the request has been to take the thrilling new roles from Avalon and make them available for The Resistance. This is now available - the Assassin module of Hidden Agenda has all the Avalon roles, rethemed and renamed to fit into The Resistance Universe.
Defector Module: Two variants in one, the Defectors were incorporated as part of the Avalon promos. In one option, the Defectors can switch allegiance during the game - ensuring that players are never certain on who to trust. In the second optional version the two Defectors know each other - ensuring that the accusations of deceit begin from the very opening of the game.
Trapper Module: Every proposed Mission Team has an extra person that won't go on the mission. The leader will segregate a team member and watch their every move - making sure they can't make the mission fail. If you are a spy on the Mission Team, you will never know if you will cause a mission to fail or be giving your identity away. But resistance members will have to approve some missions knowing that a spy is participating in them and trust that the leader chooses to isolate the spy.