He moved to the trees. Where the bark was peeling from the trunks it lifted in tiny tendrils, almost fluffs. Brian plucked some of them loose, rolled them in his fingers. They seemed flammable, dry and nearly powdery. He pulled and twisted bits off the trees, packing them in one hand while he picked them with the other, picking and gathering until he had a wad close to the size of a baseball. Then he went back into the shelter and arranged the ball of birchbark peelings at the base of the black rock. As an afterthought he threw in the remains of the twenty-dollar bill. He struck and a stream of sparks fell into the bark and quickly died. But this time one spark fell on one small hair of dry bark--almost a thread of bark--and seemed to glow a bit brighter before it died. The material had to be finer. There had to be a soft and incredibly fine nest for the sparks. I must make a home for the sparks, he thought. A perfect home or they won't stay, they won't make fire. He started ripping the bark, using his fingernails at first, and when that didn't work he used the sharp edge of the hatchet, cutting the bark in thin slivers, hairs so fine they were almost not there. It was painstaking work, slow work, and he stayed with it for over two hours. Twice he stopped for a handful of berries and once to go to the lake for a drink. Then back to work, the sun on his back, until at last he had a ball of fluff as big as a grapefruit--dry birchbark fluff.