of the Med Ship. It bore on through space.
There were tiny noises from the communicator. There were whisperings
and rustlings and the occasional strange and sometimes beautiful
musical notes whose origin is yet obscure, but which, since they are
carried by electromagnetic radiation of wildly varying wave lengths,
are not likely to be the fabled music of the spheres.

In fifteen minutes a different voice came from the speaker.

"Med Ship _Aesclipus_! Med Ship _Aesclipus_!"

Calhoun answered and the voice said anxiously:

"Sorry about the challenge, but we have the blueskin problem always
with us. We have to be extremely careful! Will you come in, please?"

"I'm on my way," said Calhoun.

"The planetary health authorities," said the voice, more anxiously
still, "are very anxious to be cooperative. We need Med Service help!
We lose a lot of sleep over the blueskin! Could you tell us the name
of the last Med Ship to land here, and its inspector, and when that
inspection was made? We want to look up the record of the event to be
able to assist you in every possible way."

"He's lying," Calhoun told Murgatroyd, "but he's more scared than
hostile."

He picked up the order folio on Weald Three. He gave the information
about the last Med Ship visit.

"What?" he asked, "is a blueskin?"

He'd read the folio on Weald, of course, but as the ship swam onward
through emptiness he went through it again. The last medical
inspection had been only perfunctory. Twelve years earlier--instead of
three--a Med Ship had landed on Weald. There had been official
conferences with health officials. There was a report on the birth
rate, the death rate, the anomaly rate, and a breakdown of all
reported communicable diseases. But that was all. There were no
special comments and no overall picture.

Presently Calhoun found the word in a Sector dictionary, where words
of only local usage were to be found:

"_Blueskin: Colloquial term for a person recovered from a plague
which left large patches of blue pigment irregularly distributed
over the body. Especially, inhabitants of Dara. The condition is
said to be caused by a chronic, nonfatal form of Dara plague and
has been said to be noninfectious, though this is not certain. The
etiology of Dara plague has not been worked out. The blueskin
condition is hereditary but not a genetic modification, as markings
appear in non-Mendelian distributions_."