I had supposed that this step would be easy, after all that has gone before—just warp the little 4-shaft loom, knock out a few yards of plain weave, and complete the torah bands. Two small things happened, though. The heddles on all four shafts were twisted together in several places. I hadn't noticed this before, because the only project I'd previously woven on this loom was a narrow sample. The heddles had been put on the frames by the person from whom I'd bought the loom, and I can only assume that this person had very bad eyesight. I removed all four shafts from the loom and rehung the heddles.
Then I completed the threading and sleying, and found that (after 43 years of weaving) I had made the number one beginner's mistake: forgot to take the warp over the back beam on its way to the shafts. So I had to unscrew the back beam and reroute the warp.
But finally the weaving is underway. OK, it's plain weave. But it will be the right weave for the job.