e they may go out entirely!"

"Do you think that you can pull away from them, Conway?" Clio was
staring in horrified fascination into the plate, watching the pictured
vessel increase in size, moment by moment.

"I don't know whether I can or not, but I'm going to try. Just in case
we don't, though, I'm going to keep on yelling for help. In solid? All
right, boat, DO YOUR STUFF!"

CHAPTER 19

GIANTS MEET

"Check your blast, Fred, I think that I hear something trying to come
through!" Cleveland called out, sharply. For days the _Boise_ had torn
through the illimitable reaches of empty space, and now the long vigil
of the keen-eared listeners was to be ended. Rodebush cut off his power,
and through the crackling roar of tube noise an almost inaudible voice
made itself heard.

"... all the help you can give us. Samms--Cleveland--Rodebush--anybody
of Triplanetary who can hear me, listen! This is Costigan, with Miss
Marsden and Captain Bradley, heading for where we think the sun is, from
right ascension about six hours, declination about plus fourteen
degrees. Distance unknown, but probably a good many light-years. Trace
my call. One Nevian ship is overhauling us slowly, another is coming
toward us from the sun. We may or may not be able to dodge it, but we
need all the help you can give us. Samms--Rodebush--Cleveland--anybody
of Triplanetary...."

Endlessly the faint, faint voice went on, but Rodebush and Cleveland
were no longer listening. Sensitive ultra-loops had been swung, and
along the indicated line shot Triplanetary's super-ship at a velocity
which she had never before even approached; the utterly
incomprehensible, almost incalculable velocity attained by inertialess
matter driven through an almost perfect vacuum by the _Boise's_ maximum
projector blasts--a blast which would lift her stupendous normal tonnage
against a gravity five times that of Earth. At the full frightful
measure of that velocity the super-ship literally annihilated distance,
while ahead of her the furiously driven spy-ray beam fanned out in quest
of the three Triplanetarians who were calling for help.

"Got any idea how fast we're going?" Rodebush demanded, glancing up for
an instant from the observation plate. "We should be able to see him,
since we could hear him, and our range is certainly as great as anything
he can have."

"No. Can't figure velocity without any reliable data on how many atoms
of matter exist per cubic mete