twisted, and went erratically off
their courses. All seemed uncontrolled momentarily.

The five scouts, following orders, darted instantly toward the Lunar
Bank. Why, they did not know. But those were orders. They were to land
there.

The reason was that, faster than any Solarian ship, radio signals had
reached McLaurin, and he, and most of the staff of the IP service had
been moved to the Lunar Bank. Buck Kendall had extended an invitation in
this "unexpected emergency." It so happened that Buck Kendall's
invitation got there before any description of the Strangers, or their
actions had arrived. The staff was somewhat puzzled as to how this
happened--

And now for the satellites of great Jupiter.

One hundred and fifty giant interstellar cruisers advanced on Callisto.
They didn't pause to investigate the mines and scattered farms of the
satellite, but ten great ships settled, and a horde of warriors began
pouring out.

One hundred and forty ships reached Ganymede. One hundred and thirty
sailed on. One hundred and thirty ships reached Europa--and they sailed
on hurriedly, one hundred and twenty-nine of them. Gresth Gkae did not
know it then, but the fleet had lost its first ship. The IP station on
Europa had spoken back.

They sailed in, a mighty armada, and the first dropped through Europa's
thin, frozen atmosphere. They spotted the dome of the station, and a
neutron ray lashed out at it. On the other, undefended worlds, this had
been effective. Here--it was answered by ten five-foot UV rays. Further,
these men had learned something from the destruction of the cruisers,
and ten torpedoes had been unloaded, reloaded with atostor mercury, and
sent out bravely.

Easily the Mirans wiped out the first torpedo--

Shrieking, the Miran pilots clawed their way from the controls as the
fearful flood of ultra-violet light struck their unaccustomed skins.
Others too felt that burning flood.

The second torpedo they caught and deflected on a beam of
alternating-current magnetism that repelled it. It did not come nearer
than half a mile to the ship. The third they turned their deflecting
beam on--and something went strangely wrong with the beam. It pulled
that torpedo toward the ship with a sickening acceleration--and the
torpedo exploded in that frightful violet flame.

* * * * *

Five-foot diameter UV beams are nothing to play with. The Mirans were
dodging these now as they loosed ato