The scenario “A Tear for Ossir”

I'm stuck at the marker next to the stairs. The first time, I was told: "Move back 2 steps and start digging." I dug all around – nothing. The second time, at the same marker, I was told: "In the darkness of the dungeons, the fallen cannot see beyond their own nose." In the tavern, I was told that the Tear is in the Lava Fields. Where should I go after this marker? People, help!