Despite our proximity to the finish line, today was as tough a day as we've ever had out here. The weather was similar to yesterday, though with a cold wind (at our backs, luckily) that stayed until the early evening, when it calmed down and things warmed up a bit. Starting the day was incredibly hard, and I was in equal parts relieved and distressed to hear that Tarka was struggling with the same weary lethargy and flagging mojo that I was.

Objectively, we're both in no doubt that our extreme physical fatigue is dragging our emotional states down, but we've both shared an unusual feeling lately of something approaching disappointment; we'd perhaps hoped Antarctica would hold more moments of beauty and joy, but the reality is that this has been - for the most part - a vast challenge that has taken us to the very outer fringes of our physical and mental endurance. Exploring those seldom-trod human realms has been a fascinating journey, but it's a frustratingly hard story to convey, as no one will ever know what it was truly like for us.

The other side of this frustration, however, is a bond with Tarka that I'll share for life. "Closer to home, closer to home", was a mantra that I started repeating to myself with each stride today, part-way through a 45-minute session that I began to fear I couldn't make it to the end of. We both fell over again on invisible sastrugi in the flat light, and at one point I feared I might have broken a bone in my forearm. These last days are proving as difficult as any that have preceded them. And speaking of last days, we plan to finish our very final one at the shore of Ross Island, by the New Zealand Antarctic station Scott Base.

It seems a logical - and historically relevant - spot to finish as it's the same point Scott would have aimed for (and the one that Shackleton and Wild reached in late February 1909 before being picked up by boat, as Scott would have been). It's impossible for us to walk from here to Scott's Terra Nova hut as we're at the end of the summer and McMurdo Sound is now open water, just as it was a century ago (though there's also an American icebreaker that burns 4,500 gallons of fuel per hour keeping the Sound ice-free these days too).

The aircraft we've chartered to take us back to Chile can't pick us up from here until the 8th, so we've decided to split tomorrow's giant day into two normal days, and we should arrive at Scott Base on the evening (UK time) of Thursday 6th. Keep your eye on the map!