Next, the elevator goes up to B1, where the door with the golden horse beside it takes Heisenberg's Key. Treat that door as one-way: a boss fight follows, and there may be no way back down to these floors. Before you ride up, finish the M1851 Wolfsbane – Long Barrel (Operating Room), the factory labyrinth (Bister Skull), Development Notes 1 and 2, the Goat of Warding in the Ventilation Duct and Quit Hanging Around. Optional: the Generator Room Walkway fridge, the Private Passageway drawer, both factory Lockpicks, the Mechanical Parts and Heisenberg's Hammer, the fenced stash in the Large Power Regulator Room, the MB3 crystal cache, the crystals by the drill and the Yellow Quartz in the Large Power Regulator Room, the Materials Room, the Ventilation Duct and Walkway Access. The elevator-shaft goat gets one more chance later in this factory. Upgrade your weapons with the Duke before you go through.