Help in Chamber 9 of Castle Haunt II

I can't find the nightmare key for the life of me. I'm pretty sure I've gotten all of the other treasures, and can find my way to two rooms containing two sword crystals and an octorock on crack, but I'm always on the wrong side of these rooms, and can't activate the crystals because I'm stuck behind a barrier. The only other rooms I can't get to are near the boss and one room in the upper-right of the first floor. I imagine I'm missing a staircase or two hidden somewhere, but I've tried to lens everything with no luck.

On the first floor in the right cheek look at the floor
drop down and move the statue :)