After being unable to move, talk, or otherwise function in the hospital for over a decade, B.J. finally (and instantaneously) regains his mobility when a group of Nazis raid the hospital, kill the doctors, and capture his caretaker. As you might expect, this sets B.J. off, allowing you to gun down the aggressors and rescue the damsel in distress. Once the bloodlust wears off, he realizes the world is much different than when he left it. The Nazis have completely taken over the world, and you need to find a way to overthrow them.
From here, you hit the road looking for any remaining resistance forces, so you can gather up your allies and hunt down Hitler. But before you find your lost comrades, you'll need to break through multiple Nazi guard checkpoints, battle even more highly advanced enemy soldiers with 1960s tech, and then face off against two giant robots armed with equally massive rapid-fire laser cannons for arms. There will definitely be a lot of guns blazing, but that isn't everything Wolfenstein has going for it.