itiative, but were willing to follow wherever the more valiant spirits
led. It was decided that no attempt should be made to salvage any
portion of the _Arcturus_, since any such attempt would be fraught with
danger and since the wreckage would be of little value. The new vessel
was to be rocket driven and was to be built of Callistonian alloys.
Personal belongings were moved into lifeboats, doors were closed, and
there ensued a painful period of waiting and suspense.

The stated hour was reached without event--no hexan scout had come
close enough to them to detect the low-tension radiation of the vital
machinery of the _Arcturus_, cut as it was to the irreducible minimum
and quite effectively grounded as it was by the enormous mass of her
shielding armor. At a signal from Captain Czuv the pilot of each
lifeboat shot his tiny craft out into space and took his allotted place
in the formation following closely behind the _Bzarvk_, flying toward
Europa, now so large in the field of vision that she resembled more a
world than a moon. Captain King, in the Callistonian vessel, transmitted
to Breckenridge the route and flight data given him by the navigator of
the winged craft. The chief pilot, flying "point," in turn relayed more
detailed instructions to the less experienced pilots of the other
lifeboats.

Soon the surface of Europa lay beneath them; a rugged, cratered, and
torn topography of mighty ranges of volcanic mountains. Most of the
craters were cold and lifeless; but here and there a plume of smoke
and steam betrayed the presence of vast, quiescent forces. Straight
down one of those gigantic lifeless shafts the fleet of space craft
dropped--straight down a full two miles before the landing signal was
given. At the bottom of the shaft a section of the rocky wall swung
aside, revealing the yawning black mouth of a horizontal tunnel. At
intervals upon its roof there winked into being almost invisible points
of light. Along that line of lights the lifeboats felt their way, coming
finally into a huge cavern, against one sheer metal wall of which they
parked in an orderly row. Roll was called, and the terrestrials walked,
as well as they could in the feeble gravity of the satellite, across the
vast chamber and into a conveyance somewhat resembling a railway coach,
which darted away as soon as the doors were shut. For hundreds of miles
that strange tunnel extended, and as the car shot along door after door
of natural rock