FATMAP difficulty grade
The isolated nature is evidenced by the fact that this route is from an unguarded bivouac hut, adding to the effort and logistical challenge.
Steep S facing slopes are unavoidable in descent so an early start is essential.
It is a complicated route with many different sections of skis on and off, so slick transitions are crucial to keep to time. Skin up easily above the hut in the dark, then traverse L to the base of then up to, usually on foot, the Aletschjoch at 3614m.
Dramatic views unfold to the N of the huge glaciers and the Jungfrau and her neighbours.
Continue for another half an hour or so along the gently rising ridge to your L, before a snowy flattening where you can put skis on again.
There are 2 option, either direct over the foresummit, or more easily outflanking it to the L which may involve a short section of bootpacking close to the top some huge seracs, which lie just below.
Skin on again for the final section to the mixed ridge starting to the R of the summit in ascent.
This is reasonably straightforward, leading to the summit cross.
Descent is often the reverse of ascent but in ideal conditions you can miss out the ridge after the col by dropping down very steeply just before it, to the skiers L of some steep ice and seracs.
Either reverse your route to the hut or, if you have everything with you, descend skiers R on open slopes to go down directly to the valley floor below the hut.
The descent can only be safely done in the morning, so a second night in the hut may be needed.
If descending out that day there are a couple of possible exits.
Described here is the route to Bettmeralp.
Continue down as for the day before to the Aletsch Glacier, then continue to descend to about 1900m, crossing the glacier in the process (tracks often in).
This accesses the tiring 400m skin up through saplings to the col at 2290m, then easy slopes on pistes down to Bettmeralp.