g--"

"I'm coming in," said Calhoun. "Give me the coordinates."

He wrote them down. His expression was slightly pained. The Med Ship
drove on, in solar system drive. Murgatroyd said, "_Chee-chee? Chee?_"

Calhoun sighed.

"That's right, Murgatroyd! Here we go again!"

* * * * *

FEAR RIDES THE ROCKETS

The Interstellar Medical Service was just about the only remaining
galactic organization that every one of the hundreds of inhabited
planets respected. So when their service broke down in Star Sector
Twelve, it created a very dangerous situation.

When Calhoun took his Med ship out of overdrive near that sector's
planet Weald, he was vaguely aware of the risks. But the crisis came
home to him with a crash the moment he radioed in for landing
coordinates.

"Contamination! Full mobilization! Red alert! Death to blueskins!"
Such were the nature of his greetings.

And it began to look like a case of the cosmic jitters that only the
most drastic of orbital surgery could cure.

Murray Leinster, whose real name is Will F. Jenkins, has been
entertaining the public with his exciting fiction for several decades.
Called the dean of modern science-fiction, he was writing these
amazing super-science adventures back in the early twenties before
there ever was such a thing as an all-fantasy magazine. His short
stories, novelettes, and serial novels have appeared in most of the
major American magazines, both slick and pulp, and many have been
reprinted all over the world. He has made a distinguished name for
himself (or rather two names) in the fields of adventure, historical,
western, sea, and suspense stories.

Ace Books has still available the following Murray Leinster novels:
CITY ON THE MOON (D-277), THE PIRATES OF ZAN and THE MUTANT WEAPON
(D-403), and THE FORGOTTEN PLANET (D-528).

* * * * *

Here's a quick checklist of recent releases of
ACE SCIENCE-FICTION BOOKS

35c

D-498 GALACTIC DERELICT by Andre Norton

D-504 MASTER OF THE WORLD by Jules Verne

D-507 MEETING AT INFINITY by John Brunner
_and_ BEYOND THE SILVER SKY by Kenneth Bulmer

D-508 MORE MACABRE Edited by Donald A. Wollheim

D-509 THE BEAST MASTER by Andre Norton
_and_ STAR HUNTER by Andre Norton

D-516 THE SWORDSMAN OF MARS
by Otis Adelbert Kline

D-517 BRING BACK YESTERDAY by A. Bertram Chandler
_and_ THE TROUBLE WITH TYCHO by Clifford Simak