said. "We've got to get out of here. If they break
in, we're done for."

"They can't break through the screen," Dal said.

"Not as long as it lasts. But we can't keep it up indefinitely."

Once again they tried the radio equipment. There was no response but the
harsh static of the jamming signal from the ground below. "It's no
good," Tiger said finally. "We're stuck here, and we can't even call for
help. You'd think if they were so scared of us they'd be glad to see us
go."

"I think there's more to it than that," Dal said thoughtfully. "This
whole business has been crazy from the start. This just fits in with all
the rest." He picked Fuzzy off his perch and set him on his shoulder as
if to protect him from some unsuspected threat. "Maybe they're afraid of
us, I don't know. But I think they're afraid of something else a whole
lot worse."

* * * * *

There was nothing to be done but wait and stare hopelessly at the mass
of notes and records that they had collected on the people of 31 Brucker
VII and the plague that afflicted them.

Until now, the _Lancet_'s crew had been too busy to stop and piece the
data together, to try to see the picture as a whole. But now there was
ample time, and the realization of what had been happening here began to
dawn on them.

They had followed the well-established principles step by step in
studying these incredible people, and nothing had come out as it should.
In theory, the steps they had taken should have yielded the answer. They
had come to a planet where an entire population was threatened with a
dreadful disease. They had identified the disease, found and isolated
the virus that caused it, and then developed an antibody that
effectively destroyed the virus--in the laboratory. But when they had
tried to apply the antibody in the afflicted patients, the response had
been totally unexpected. They had stopped the march of death among those
they had inoculated, and had produced instead a condition that the
people seemed to dread far more than death.

"Let's face it," Dal said, "we bungled it somehow. We should have had
help here right from the start. I don't know where we went wrong, but
we've done something."

"Well, it wasn't your fault," Jack said gloomily. "If we had the right
diagnosis, this wouldn't have happened. And I _still_ can't see the
diagnosis. All I've been able to come up with is a nice mess."

"We're missing something, that's