But the shyest and most self-effacing of the wall community were the most dangerous; you hardly ever saw one unless you looked for it, and yet there must have been several hundred living in the cracks of the wall. Slide a knife-blade carefully under a piece of the loose plaster and lever it gently away from the brick, and there, crouching beneath it, would be a little black scorpion an inch long, looking as though he were made of polished chocolate. They were weird looking things, with their flattened, oval bodies, their neat, crooked legs, the enormous crab-like claws, bulbous and jointed neatly as armor, and the tail like a string of brown beads ending in a sting like a rose thorn. 