High in the stratosphere, speeding eastward, the immense mass of the _Boise_ slowed abruptly, although no projector had slackened its effort. Cleveland, eyes upon interferometer grating and spectrophotometer charts, fingers flying over calculator keys, grinned as he turned toward Rodebush. "Just as you thought, Skipper; an ultra-band pusher. C4V63L29. Shall I give him a little pull?" "Not yet; let's feel him out a little before we force a close-up. We've got plenty of mass. See what he does when I put full push on the projectors." As the full power of the Terrestrial vessel was applied the Nevian was forced backward, away from the threatened city, against the full drive of her every projector. Soon, however, the advance was again checked, and both scientists read the reason upon their plates. The enemy had put down re-enforcing rods of tremendous power. Three compression members spread out fanwise behind her, bracing her against the low mountainside, while one huge tractor beam was thrust directly downward, holding in an unbreakable grip a cylinder of earth extending deep down into bedrock. "Two can play at that game!" And Rodebush drove down similar beams, and forward-reaching tractors as well. "Strap yourselves in solid, everybody!" he sounded a general warning. "Something is going to give way somewhere soon, and when it does we'll get a jolt!" And the promised jolt did indeed come soon. Prodigiously massive and powerful as the Nevian was, the _Boise_ was even more massive and more powerful; and as the already enormous energy feeding the tractors, pushers, and projectors was raised to its inconceivable maximum, the vessel of the enemy was hurled upward, backward; and that of earth shot ahead with a bounding leap that threatened to strain even her mighty members. The Nevian anchor-rods had not broken; they had simply pulled up the vast cylinders of solid rock that had formed their anchorages. "Grab him now!" Rodebush yelled, and even while an avalanche of falling rock was burying the countryside, Cleveland snapped a tractor ray upon the flying fish and pulled tentatively. Nor did the Nevian now seem averse to coming to grips. The two warring super-dreadnaughts darted toward each other, and from the invader there flooded out the dread crimson opacity which had theretofore meant the doom of all things Solarian. It flooded out and engulfed the immense mass of humanity's hope in its spreading cloud of redly impenetrable murk. But not for long. Triplanetary's super-ship boasted no ordinary Terrestrial defense, but was sheathed in screen after screen of ultra-vibrations: imponderable walls, it is true, but barriers impenetrable to any unfriendly wave. To the outer screen the red veil of the Nevians clung tenaciously, licking greedily at every square inch of the shielding sphere of force, but unable to find an opening through which to feed upon the steel of the _Boise_'s armor.