Yesterday [9/4/2016] Andrew and I took a route that is normally completed as a multi-day backpacking trip and completed it in under 24 hours.
I call it the Super Pemi, though our friend Dan M. called it the Super-Extended Pemi Loop (you can read his trip report here ). Basically, you take an extended Pemi and add on North Twin, Hale, and Zealand (or the reverse), which adds on 12 miles and over 4,000' of climbing. The abandoned Fire Warden's trail on Hale allows one to connect the North Twin Trail to Hale, therefore closing out the loop. All told, you net 13 NH 4Ks, 44.4 miles, and 14,750-15,000'+ of elevation gain (depends on which device you look at).
Depending on direction of travel, this loop is completed by either:
Clockwise: From S. Twin, take N. Twin Spur to N. Twin.
Descend N. Twin trail to where the herdpath splits right, follow herdpath.
Take FW trail from herdpath to Hale summit.
Lend-A-Hand to Twinway
Twinway to Zealand, and finally back to the Bondcliff trail.
Obviously, you'd reverse these directions if travelling counter-clockwise.
We completed the entire loop in 15:15:50, going counter-clockwise (Bondcliff first). We didn't do this with the intention of setting an unbreakable FKT or anything, as most of the day was fast walking with some jogging, but we finished with a solid 3 mph pace over the 44.4 miles. I'm sure someone will go out and smash our time, but I figured we could at least set a precedent. It'll be fun to see how much faster someone else crushes this variation of the oh-so-popular Pemi Loop.