Bird with flowing tail on upper back

The snow came down the Kessar pass two days after you left, so the mules crossed the col on Tuesday with their ears flat and nobody talking. I am writing this at the inn at Lower Vell, where the stove smokes but the beds are dry. Mother will want to know whether I ate. I have.

Something odd happened on the ascent. Halfway up the zigzag, where the path hangs over the gorge, a bird came out of the cloud and kept pace with us. It was pale grey, slender as a pen stroke, with its wings swept back like a blade and two long tail feathers trailing behind, nearly to the rock below. Old Pieter said it was a snow finch, but finches do not fly that high, and I have never seen one with a tail like a ribbon. It flew ahead of the lead mule and circled back, always just below the cornice, until we reached the cairn.

Then it dropped into the gorge and was gone, and the mules went quiet in a different way, as if they had been waiting for it too.

Pieter says a bird that guides a caravan over the pass means the pass will not take anyone this year. I told him that was a fine thing to believe on a clear morning, and he laughed, and then we both looked back at the cloud. Keep the lamp lit for me, Tomas. I will be home before the thaw, and I will bring you the ribbon feather if I can find it.