Lots of fun. A crack line that climbs like a face climb with interesting moves. A good one to add if you're in the IRS Wall area. You can reach the base from IRS wall by walking right and sort of behind Copenhagen, up through a notch in the cliffline, and then back along the base of Copenhagen, (the notch puts you out at the right side of the Copenhagen wall).
Gear anchor - I used a #1, #2, #3 camalot. Down climb chimney south or rap from new anchors above Butterflies are Free (left of It Satisfies). Pro extra small stoppers to #2 camelot.
Going up the thin crack left then traversing right has good gear 5.10b/c and makes sense. Following the thin crack right 5.10c/d I couldn't find gear and didn't make any sense except to lunge (Quantum Jump?) for a manky finger lock and big foothold which is way scary.