Heimdall: It does look familar I wonder.
*Heimdall draws his sword and holds it tip down right in front of the impression. What seems to be a strong magnetic force pulls the sword free of Heimdall and right into the impression. The rock wall envelopes the sword and the blade is completly swallowed by the wall.
Once that happens the wall swings backwards revealing another passage way. This passage was not that of a rough mining tunnel. Instead the floor was highly polished, the walls were straight and smooth. crystals jutting from the wall were luminous providing light.*
Heimdall: It did say it was a key, guess this is what it unlocked. So lets go forward.
*Heimdall enters the new passage while drawing his blaster*
"Dulce bellum inexpertis."
Official Forum Expert on Norse Mythology
As Odin says in the Hovamal:
"Praise no day 'til evening; no wife 'til on her pyre; no sword 'til tested;
no maid 'til bedded; no ice 'til crossed;
no ale 'til drunk."