During the second campaign mission titled, Celerium players can find Thor's hammer in a cave a short distance from where they land after gliding in.
Hidden in a cave close to where you land players will find Thor’s hammer stuck in the ground. When you initially find the easter egg you won’t be able to interact with it, and to see it you may need a night vision scope as the cave is very dark.
In order to activate the hammer players must silently kill all the guards in the first section (use suppressors). Once you’ve done this Harper and Manson will discuss how the enemy detected they were losing men and your character will become detected. After being detected return to Thor’s hammer and you will now be able to interact with it. After you attempt to use the hammer a prompt will appear on the screen which reads, “You are not worthy.”