Decided it was time for a final trip in 148 to push the remaining lead to a conclusion and derig. So we packed all the rope in the bivi into a very full bag and set off. We used a boulder and a spike as backups, then I climbed down the rift, used another spike as a backup and stuck in a spit for the hang. This got me down to where I'd been already via the alternate tight thrutchy route. A rebelay off a thread reached the boulder-strewn chamber floor. I followed the rift off the far side, round a corner to the left, and it ended, far too tight. Shouted to Jenny that it was over, then returning noticed a tight hold down into the rift, partly hidden by the nose of a huge slab of fallen rock. A really strong icy draught blasted up from it! Jenny sounded a little disappointed that it wasn't really over. A y-hang on spits and some awkward squirming reached a nicely proportioned pitch. At the base, the floor was mostly clean-washed rock, with a gravel bank to one side. The water flowed down a small hole, but a climb up regained the rift. Round the corner to the left, the floor dropped away. Stones rattle down the initial rift, then freefall for perhaps 4 seconds (starting to whistle) then hit something solid, then fell for another similar length of time. Hard to judge the total depth, but a substantal pitch, and the 44m rope we had left wasn't going to reach, so we surveyed out and planned to go back to base for more rope.