This becomes available after you receive some spam messages from Al Gore upon completion of Manbearpig. Head back to his hideout and talk to him. You'll have to fight him and his secret service agents.
For the first turn, block Al Gore's attempt to bore you and inflict Sleep and Screwed statuses on your characters. Don't use Shock against them. Use Burning and Gross Out instead. Take out the specialist s first since their rifle shots are unblockable. The Secret Service Agent has some wicked combos and can use a stun grenade.
Al Gore also regenerates but don't mind him until you take out his minions. Use a Speed Potion to allow you to attack again. You must attempt this once you have powerful weapons and equipment in your possession. Once his minions are out, you can focus on taking out Al Gore.
After taking him out, loot his body and his Secret Room Key. Open his room and loot the chest there.