"You cannot return.
"I did this to you and you may hate me for it; I do not know. That is up to you to decide, but it does not matter. What does matter, and not to you alone, is another decision which you must make. I am incapable of making it.
"Who is writing this to you? I would rather not tell you just yet. By the time you have finished reading this, even though it is not signed (for I knew you would look first for a signature), I will not need to tell you who I am. You will know.
"I am seventy-five years of age. I have, in this year 2004, been studying 'time' for thirty of those years. I have completed the first time machine ever built—and thus far, its construction, even the fact that it has been constructed, is my own secret.
"You have just participated in the first major experiment. It will be your responsibility to decide whether there shall ever be any more experiments with it, whether it should be given to the world, or whether it should be destroyed and never used again."
End of the first page. You look up for a moment, hesitating to turn the next page. Already you suspect what is coming.
You turn the page.
"I constructed the first time machine a week ago. My calculations had told me that it would work, but not how it would work. I had expected it to send an object back in time—it works backward in time only, not forward—physically unchanged and intact.
"My first experiment showed me my error. I placed a cube of metal in the machine—it was a miniature of the one you just walked out of—and set the machine to go backward ten years. I flicked the switch and opened the door, expecting to find the cube vanished. Instead I found it had crumbled to powder.