The Unforgiven is a three star pitch on the east face of Nuns (perhaps worth four if done as a logical second pitch to Holier Than Thou - see that description).
Climb the first pitch of Holier Than Thou (also 11c), then continue slightly right and straight up past 6 silver bolts before traversing right to gain a diagonaling finger crack which leads to the top of the face. The climbing is technical, fingery, and quite sustained.
One can rap from the summit in three raps with a single 70m rope - the final rap is rope-stretching.
Also, be aware that a lot of the rock is suspect on the Nuns - I fell twice ripping off holds on this pitch, and my partner fell once doing the same. The climbing is really good in spite of this though... I swear.
P.S. I climbed this again in 2007 and the pitch has either cleaned up a lot or my climbing has cleaned up a lot. Probably the latter. But in any case, I didn't rip a single hold off. Oh, and anyone who claims calcite is slippery needs to sample this climb -- the best friction I've ever seen.
Wear a helmet and don't leave anything you care about at the base of the climb. Very sustained steep slabbing. At some points the calcite is so thick that it could be fairly called Limestone.