A Blue Streak

I crawled under the garden gate out onto the wide public sidewalk. The pale concrete stretched far ahead under the midday sun. Right beside an expansion seam lay a thick cylinder of chalk. I stopped. I reached out and gave the blunt tip a firm shove with my right claw. The chalk dragged against the rough paving stone with a dry scraping hiss. A bright blue streak appeared behind it on the grey cement. I paused, watching the fresh color. I planted both claws and pushed it forward in a wide arc. A broad blue curve now wrapped across the pavement, marking the stone.