he fullest. If Dr. Ch'ien could finish his work, travel to
the stars would no longer be a wild-eyed idea; if he could finish,
spatial velocities would no longer be limited to the confines of the
rocket, nor even to the confines of the velocity of light. Man could go
to the stars.

The United States Federal Government knew--or, at least, the most
responsible officers of that government knew--that Ch'ien's equations
led to interstellar travel, just as Einstein's equations had led to
atomic energy. Normally, the United States would never have allowed Dr.
Ch'ien to attend the International Physicists Conference in Peiping. But
diplomacy has its rules, too.

Ch'ien had published his preliminary work--a series of highly abstruse
and very controversial equations--back in '80. The paper had appeared in
a journal that was circulated only in the United States and was not read
by the majority of mathematical physicists. Like the work of Dr. Fred
Hoyle, thirty years before, it had been laughed at by the majority of
the men in the field. Unlike Hoyle's work, it had never received any
publicity. Ch'ien's paper had remained buried.

In '81, Ch'ien had realized the importance of his work, having carried
it further. He had reported his findings to the proper authorities of
the United States Government, and had convinced that particular branch
of the government that his work had useful validity. But it was too late
to cover up the hints that he had already published.

Dr. James Ch'ien was a friendly, gregarious man. He liked to go to
conventions and discuss his work with his colleagues. He was, in
addition, a man who would never let anything go once he had got hold of
it, unless he was convinced that he was up a blind alley. And, as far as
Dr. Ch'ien was concerned, that took a devil of a lot of convincing.

The United States government was, therefore, faced with a dilemma. If
they let Ch'ien go to the International Conferences, there was the
chance that he would be forced, in some way, to divulge secrets that
were vital to the national defense of the United States. On the other
hand, if they forbade him to go, the Communist governments would suspect
that Ch'ien knew something important, and they would check back on his
previous work and find his publications of 1980. If they did, and
realized the importance of that paper, they might be able to solve the
secret of the interstellar drive.

The United States government had figurativel