As the game begins, you have smuggled yourself into the Eagle's Nest and are safe for the moment in a small storage room on the ground floor. You are armed and have 99 rounds of ammunition, hardly enough to make a dent in the Nazi hordes you hear in the hallway outside. You are in good health, and luckily, the key to the steel door in front of you is in easy reach.
When you first enter the game, you will start with the first of four missions inside the first castle. Missions one, two, and three each involve the rescue of one of the prisoners, and mission four is to blow up the castle. You will enter a second castle with four new missions once you successfully destroy the first castle.