Also just after Sierra City, we started to see a huge plume of smoke in the distance. My knee also began to hurt more and more again. We eventually decided to take a break at a B&B near Bucks Lake, 20 miles before Belden. There we found out that there was a giant wildfire ahead, and we'd have to skip to Chester. We took a full day off, got a ride to Quincy, and took a bus to Chester. I went to a doctor there who told me I probably had a torn meniscus, which worried me a lot. We decided to come back to the Bay Area to check it out. Our friends Carlo and Francesca drove up, explored Lassen with us for a day, and dropped us off in Berkeley last Sunday.
Fortunately, the real knee specialist I managed to see on Monday told me that I just had tendinitis (of the group of tendons called the pes anserinus), not a torn meniscus. After a week of rest, ibuprofen, and icing, it feels pretty good. We are figuring out when and where we want to get back to the trail (we don't have time to start where we left and make it before the snow, probably) and will post another update once we're sure about that.