what does "pretty tightly wound "mean? “But instead,” he said, “you waited. You waited all that evening, having watched her leave the building. You must have been pretty tightly wound by then. You’d had time to formulate a rough plan. You’d been watching the street; you knew exactly who was in the building, and who wasn’t; you’d worked out that there might just be a means of getting clean away, without anyone being the wiser. And let’s not forget—you’d killed before. That makes a difference.”