As the girl left the room, Peter absently watched the swaying of her hips as she walked, but he was too upset to appreciate the view fully. He had a serious problem to consider. He thought over what she had said. So Quiggs had been jealous, eh? That probably explained the fact that he had left a five-dollar-bill in the safe. With his odd sense of humor, Quiggs had probably thought it very funny to leave a five note in place of the fifty thousand he had taken. There was no doubt that it was Quiggs; the police were certain of the guilty person. Quiggs had been seen coming into the office on the Thursday night before Christmas vacation and had left only half an hour later. He had evidently taken the money out and replaced it with a bundle of wrapped paper. Some hours later, he had checked out of his apartment, and all trace of him had been lost. Peter looked up at the Watteau print which concealed the heavy steel door of the wall safe. Five dollars lay behind it, all that was left of fifty thousand. He got up, walked over to the safe, twisted the combination, and pulled the door open. He reached in, took out the bill, and looked at it. And looked again, with wide eyes. Because it wasn't a five-dollar-bill, at all. It was a thin sheet of paper-like plastic, folded up to about the same size as a banknote. Puzzled, Peter looked into the safe again. Nothing. He thrust his hand in and felt around. Still nothing. Except for the sheet of stuff he held in his hand, the safe was as empty as a church on Monday. Unfolding the folded sheet, Peter saw that it was covered with print. The characters were oddly shaped, and the phraseology was queer, but it was unmistakably English. Peter Merton sat on the edge of his desk and began to read. _Honorable Mister, Miss, or Missus_: _To whoever you are in the Twentieth Century, we of the Thirtieth Century send greetings. We hope this epistle will be understandable; our knowledge of the language of English is maybe not as good as might be. Our studies of your time are somewhat hampered by lack of records, and it for this reason is that we contact you._ _In order for the Time Transfer Field to work, it must be entirely surrounded by thick metal. Also a piece of similar material must be in place so that transfer can be effected, in accordance with the Vorish Equations._ _If you wish to co-operate in this history-seeking venture, please place a note to such effect in your metal box._ _Rolath Guelph_ _Terrestrial Bureau of Historical Investigation_ Peter frowned and read the thing again. Who would write such silliness? Could it be another joke by Quiggs? No, it couldn't be; he, Peter Merton, had put that five-dollar-bill back into the safe, and he hadn't left the room while it was in there.