The surgery produced absolutely no results,” the chief surgeon said wearily, removing his gloves. “We were wrong again. And this man is dying right here on our table.”

“But how?” the physician replied irritably. “All indicators are clean. No inflammation, no tumors, no viruses. We’ve ruled out everything possible.”

They spoke as if no one else was in the room. But in the corner stood the cleaning lady — an elderly woman who had worked at the hospital for many years. She was mopping the floor, pretending not to listen. But she had heard everything.