Sniper Elite V2 Mission #4 - Opernplatz
You will have to get to Opernplatz without alerting too many enemies.
On your way to Opernplatz you will encounter a few soldiers patrolling the streets. In order to take them out, you will have to wait for the bombs to drop, just so the sound made by the shot will get covered by it and you will not get heard by the other enemies.
After dealing with the patrols, you will approach the central square with a statue in the middle, try not to get spotted by the patrols on the street and the snipers hidden in the building. In order to deal with them, you will have to take them out one by one and use the bombs drop as a cover for the sound made by your sniper rifle.
Enter the library.
Go upstairs on the second floor and head to the second hole in the wall.
You will notice Schwaiger who's about to get executed by an officer.
You will have to prevent it from happening by killing the officer and the other two soldiers
Cover Schwaiger's path to the library.
Meet him downstairs at the entrance.
Head back to the first floor and protect Schwaiger from the Russian soldiers.
At the end of the fight you will have a chat with Schwaiger, who's been hurt pretty badly. He manages to tell you about V2s, Wolff and Tabun right before he dies. The mission will end here.