to disturb Murgatroyd, he had her write down another time and sequence
of figures, only slightly different from the first. Half an hour later
still, a third set. But then he put Murgatroyd down, well satisfied.

He took his own temperature. He nodded.

"Murgatroyd and I have one more chore to do," he told her. "Would you
go in the other cabin for a moment?"

Disturbed, she went into the other cabin. Calhoun drew a small sample
of blood from the insensitive area on Murgatroyd's flank. Murgatroyd
submitted with complete confidence in the man. In ten minutes Calhoun
had diluted the sample, added an anticoagulant, shaken it up
thoroughly, and filtered it to clarity with all red and white
corpuscles removed. Another Med Ship man would have considered that
Calhoun had had Murgatroyd prepare a splendid small sample of
antibody-containing serum, in case something got out of hand. It would
assuredly take care of two patients.

But a Med Ship man would also have known that it was simply one of
those scrupulous precautions a Med Ship man takes when using cultures
from store.

Calhoun put the sample away and called Maril back.

"It was nothing," he explained, "but you might have felt
uncomfortable. We simply had a bit of Med Service routine that had to
be gone through. It's all right now."

He offered no further explanation. She said, "I'll fix lunch." She