It was a very strange looking window. It was covered with frost, but there were lines of bare window, as though the frost had been scraped away. The lines formed letters, and the letters formed words, and the words were:
POO. MOM TOLD ME.
"My God," said Marshall.
"Well, well, well, well, well," said Stevenson.
"Yes," said Professor Long. He nodded, and turned away from the window to look at the door. "You may come in now, Eddie," he called.
The door opened, and Eddie Clayhorn stood there, in civilian clothes. He beamed at the window. "That was tricky," he said.
"So," said Professor Long. "I was mistaken, eh? Exposure does not spoil things, is that it?"
"Sometimes," said Eddie Clayhorn, "the hero has one or two trusted friends on the police force who know who he is and give him tips about criminals. But they never tell anybody."
"Of course!" said Professor Long. "And we are your trusted friends. Yes?"
"Sure. But you can't tell my parents or anybody."