This took far longer, a few minutes at least, as he tensed and strained various back muscles. It was odd, trying to flex something he never knew existed a minute ago. And more than once, he simply tensed a muscle he was used to, like his shoulder. Almost by mistake, he stumbled upon the newly discovered dorsi muscle. With a faint swish of feathers against stone, which felt uncomfortably coarse, his wing was by his side again.