The letterhead, he saw without surprise, was OLIVER B. MCALLEN.

The letter read:

Dear Mr. Chard:

An unfortunate series of circumstances, combined with certain character traits in yourself, make it necessary to inconvenience you in a rather serious manner.

To explain: The information I gave you regarding the McAllen Tube and my own position was not entirely correct. It is not the intractable instrument I presented it as being—it can be "shut off" again quite readily and without any attendant difficulties. Further, the decision to conceal its existence was not reached by myself alone. For years we—that is, Mr. Fredericks, who holds a degree in engineering and was largely responsible for the actual construction of the Tube—and I, have been members of an association of which I cannot tell you too much. But I may say that it acts, among other things, as the present custodian of some of the more dangerous products of human science, and will continue to do so until a more stable period permits their safe release.

To keep developments such as the McAllen Tube out of irresponsible hands is no easy task these days, but a variety of effective devices are employed to that end. In this instance, you happened upon a "rigged" situation, which had been designed to draw action from another man, an intelligent and unscrupulous individual who lately had indicated a disturbing interest in events connected with the semipublic fiasco of my "matter transmitter" some years ago. The chances of another person becoming aware of the temporal incongruities which were being brought to this man\'s attention were regarded as so remote that they need be given no practical consideration. Nevertheless, the unexpected happened: you became interested. The promptness with which you acted on your chance observations shows a bold and imaginative manner of thinking on which you may be genuinely congratulated.

However, a perhaps less commendable motivation was also indicated. While I appeared to stall on coming to decisions you may have regarded as inevitable, your background was being investigated by the association. The investigation confirmed that you fall within a personality category of which we have the greatest reason to be wary.

Considering the extent of what you had surmised and learned, falsified though the picture was, this presented a serious problem. It was made more acute by the fact that the association is embarking on a "five-year-plan" of some importance. Publicity during this period would be more than ordinarily undesi............