How do you start these two tasks?? Sacred Plain (Dragon Age: Inquisition)

I don't remember exactly, but my magician has to burn it.

the coffin
I got two arson attacks there and captured... and here are these tasks and how to perform them xs

This is a quest, where there should be a corporal, or someone else, do not remember exactly his rank, and he says it is necessary to help disassemble with the dead their garrison.

These tasks are in the basements, you have to go down from the add-on with the pit and run around it around, you'll find the locked doors

I'm going through the game, I'm also set by this pig, in the map mark of one of the entrances and the way to reach))

This is way up to the second sign, you will need the ability to "artful hands"