Valve Corporation has previously stated that the new Payday: The Heist Mercy Hospital map is not a part of Left 4 Dead lore but it’s just an extra for players of Payday: The Heist. The Mercy Hospital heist is for anyone who owns Payday: The Heist. The map involves robbing the hospital for what I assume money or maybe medical supplies (vaccines?) I have no clue but It doesn’t really fit the traditional bank heist motif does it? I just imaging its a NHS hospital.