plz help!!!! Mourning's ends part 2

I did this quest several month ago and because of my lower agility lvl, and failed, so I dropped all crystal&mirror from quest, now I decided to try again, when I climbed over wall supports and arrived the first floor, I opened the cheset found empty, and there is nothing in the polliar.

Did that mean I only need carry on the quest from the floor i quit?
Plz help, thanks!