1. Find a disguise/papers
2. Destroy the prototype
3. Obtain level 2 papers
4. Enter the U boat
5. Destroy the U boat
O b j e c t i v e 1:
This mission is one of the most annoying level in the game. First up, press Q to holster your gun. Then enter the door and pick up the equipment. Sheesh how easy :P
O b j e c t i v e 2:
Head past the nazis who are playing cards, to the first checkpoint where a guard will ask you for papers. DON'T ignore him. Press 7 to show them (if you haven't changed that key). Then go through the door. Don't go downstairs yet, but go through the mini office to a door at the other end of the room. Enter here and wait for the door to close. Take out your MP40, eliminate the scientists, and shoot at to destroy the prototype.
O b j e c t i v e 3:
Now enter the downstairs area. Once in the supply room there is a roving officer dressed in golden-brownish attire. DO NOT TALK/GO NEAR HIM!. He will see straight through our little masquerade =/ Avoid him and proceed to the hall. Out the door you will now be in one of several sub bays. Visit the guard ahead of you as another check point. Show him the papers. Continue on until you reach another checkpoint. The guard won't let you pass. Again, don't ignore him.
So, climb the stairs to your right. Open/close the door, and shoot the guy who you need to assume identity. Pick up the papers he no longer has a need for and go back to the checkpoint.
O b j e c t i v e 4:
For some reason unknown, the complete idiot of a soldier will let you by unhindered. Turn left onto the pier and down the steps going on the sub. Climb the ladder to enter it.
O b j e c t i v e 5:
Welcome to the worlds tiniest submarine! Sigh...EA and id Software could not have put ANY less effort into drawing this sub = p
At any rate go to one of the ends of the sub. Either one will do. Take out a gun and eliminate all guards (you went to one of the ends to avoid a crossfire). Now, plant the explosives at both opposite ends then climb back up the ladder in the center of the submarine. Your cover is blown, so you'll be taking heavy fire. Exit the vessel fast unless you have some interest in exploring the bottom of the ocean. Run and don't stop running, and find cover behind the crates.
O b j e c t i v e 6:
This is the HARDEST part of the level. You have to escape with the health you have now with NO other health's to pick up and seemingly 5 million guards trying their hardest to kill you! Take cover in the crates and pick them off one by one is all I can offer. And take it slow, you have no pressing engagement, and the guards aren't endless.
Once you reach the last bay and clear out the remaining enemies, go to the last pier. Advance straight until you come to an opening. There are some stairs here, but first get the 50 health in the room on the left (this is all the health you'll have for the next level). Then climb up the stairs and into the ventilation shaft.