Before that avenging attack the Slavs, their very spine broken, bewildered and confused, already turning in panic, could not stand. America swept to the Pacific, and left death in her wake. And when she came to San Francisco, not even the sternest fighting men, still hot from battle, could repress a shudder, so awful was the devastation. The Slav invasion was over! * * * * * In the rebuilt city of San Francisco there is a statue that stands proudly before the magnificent, gleaming city hall. It represents two slim, straight-standing figures, clad in the uniform of the American Air Force. Their outstretched arms support a tiny one-seater Goshawk fighting plane. Below, as you know, there is a plaque. Men touch their hats as they walk by it; flowers are always fresh at its base. On the plaque are the words: To The Everlasting Memory Of Captain Basil Hay, A.A.F. Captain Derek Lance, A.A.F. Who, In The War Of 1938, Gave Their Lives In Destroying And Devastating San Francisco That San Francisco And America Might Live [Illustration: Advertisement.] The Tentacles From Below A COMPLETE NOVELETTE _By Anthony Gilmore_ CHAPTER I "_Machine-Fish_" [Illustration: _Bowman hooked it on the hawser arm above._] [Sidenote: Down to tremendous ocean depths goes Commander Keith Wells in his blind duel with the marauding "machine-fish."] "Full stop. Rest ready." These words glowed in vivid red against the black background of the _NX-1's_ control order-board. A wheel was spun over, a lever pulled back, and in the hull of the submarine descended the peculiar silence found only in mile-deep waters. Men rested at their posts, eyes alert. Above, in the control room, Hemingway Bowman, youthful first officer, glanced at the teleview screen and swore softly. "Keith," he said, "between you and me, I'll be damned glad when this monotonous job's over. I joined the Navy to see the world, but this charting job's giving me entirely too many close-ups of the deadest parts of it!" Commander Keith Wells. U. S. N., grinned broadly. "Well," he remarked, "in a few minutes we can call it a day--or night, rather--and then it's back to the _Falcon_ while the day shift 'sees the world.'" He turned again to his dials as Hemmy Bowman, with a sigh, resumed work. "Depth, six thousand feet. Visibility poor. Bottom eight thousand," he said into the phone hung before his lips, and fifty feet aft, in a small cubby, a blue-clad figure monotonously repeated the observations and noted them down in an official geographical survey report. * * * * * Such had been their routine for two tiring weeks, all part of the _NX-l's_ present work of re-charting the Newfoundland banks.