This is the very thin line of crimps up the overhanging wall to the left of Halcyon. Start with a sidepull and a very small right handhold and make an exceedingly hard move to a decent edge. Continue with interesting, difficult moves on decent edges to the lip, then top out and follow Halcyon up the slab to the top of the boulder. The crux is the first move, but the rest is no gimme.