again. Where it had rested
there was another discolored patch on the car seat covers.

Holding it away from him, Forster hurried into the office, then dumped
the box into a metal wastebasket. Then he went to a cabinet and pulled
out a Geiger counter, carried it over to the wastebasket. As he pointed
the probe at the box the familiar slow clicking reassured him, and
feeling a little foolish he put the instrument back on its shelf.

[Illustration: In his pressurized chamber, Forster read the startling
message.]

Hurriedly, he went through his mail; there was nothing in it referring
to the package. Then he called the classified filing section; nobody
there knew anything about it either.

For some reason he couldn't explain to himself, he wasn't even
surprised.

He stared into the wastebasket. The clumsily etched instructions glinted
up at him: "_To be opened as soon as possible...._"

He picked up the phone and called the decompression chamber building.

* * * * *

There was no valid reason why he should have been self-conscious as he
talked to the lab attendant in charge of the decompression tank. He used
it a dozen times a month for tests and experiments, yet when he gave his
instructions his voice was labored and strained.

"Some genius in Washington sent this thing down without any covering
instructions, but it has to be opened in a hurry in a thin atmosphere.
Er--I'd like you to stay on the intercom for a while in case it blows up
in my face or something." He tried to laugh, but all that came out was a
croak.

The attendant nodded indifferently, then helped Forster into the helmet
of his pressure suit. He climbed up the steps into the chamber, pulling
the airtight door shut behind him. He placed the box on the desk in
front of the instrument panel, then turned back to push the door clamps
into place.

For the first time in the hundreds of hours he'd spent in the tank, he
knew the meaning of claustrophobia.

Mechanically, he plugged in his intercom and air lines, went through the
other routine checks before ascent, tested communications with the lab
attendant, then flicked the exhaust motor switch.

Now there was little to do except wait. He stared at the box; in the
artificial light it seemed full of hidden menace, a knowing aliveness of
its own....

Forster shrugged his shoulders impatiently, as though to throw off the
vague blanket of uneasiness that was settling arou