es
unnecessary. And if the Tube was the only way in or out, then McAllen
incidentally had provided himself with an escape-proof jail for anyone
he preferred to keep confined. The place might very well have been
built several hundred feet underground. A rather expensive proposition
but, aside from that, quite feasible.

Barney felt his breath begin to quicken, and told himself to relax.
Wherever he was, he shouldn't be here long. McAllen presently would be
getting in contact with him. And then--

His glance touched the desk across the room, and now he noticed his
missing wrist watch on it. He went over, picked it up, and discovered
that the long white envelope on which the watch had been placed was
addressed to him.

For a moment he stared at the envelope. Then, his fingers shaking a
little, he tore open the envelope and pulled out the typewritten
sheets within.

* * * * *

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 semipubli