"Get back--'way back! Go back and help Pittsburgh!" Rodebush drove an ultra-communicator beam through the murk to the instruments of the Terrestrial admiral; for the surviving warships of the Fleet--its most powerful units--were hurling themselves forward, to plunge into that red destruction. "None of you will last a second in this red field. And watch out for a violet field pretty soon--it'll be worse than this. We can handle them alone, I think; but if we can't, there's nothing in the System that can help us!" And now the hitherto passive screen of the super-ship became active. At first invisible, it began to glow in livid, violet light, and as the glow brightened to unbearable intensity the entire spherical shield began to increase in size. Driven outward from the super-ship as a center, its advancing surface of seething energy consumed the crimson murk as a billow of blast-furnace heat consumes a cloud of snowflakes in the air above its shaft. Nor was the red death-mist all that was consumed. Between that ravening surface and the armor skin of the _Boise_ there was nothing. No debris, no atmosphere, no vapor, no single atom of material substance--the first time in Terrestrial experience that an absolute vacuum had ever been attained! Stubbornly contesting every foot of way lost, the Nevian fog retreated before the violet sphere of nothingness. Back and back it fell, disappearing altogether from all space as the violet tide engulfed the enemy vessel; but the flying fish did not disappear. Her triple screens flashed into furiously incandescent splendor and she entered, unscathed, that vacuous sphere, which collapsed instantly into an enormously elongated ellipsoid, at each focus a madly warring ship of space. Then in that tube of vacuum was waged a spectacular duel of ultra-weapons--weapons impotent in air, but deadly in empty space. Beams, rays, and rods of Titanic power smote cracklingly against ultra-screens equally capable. Time after time each contestant ran the gamut of the spectrum with his every available ultra-force, only to find all channels closed. For minutes the terrible struggle went on, then: "Cooper, Adlington, Spencer, Dutton!" Rodebush called into his transmitter. "Ready? Can't touch him on the ultra, so I'm going onto the macro-bands. Give him everything you have as soon as I collapse the violet. Go!"