Lensman Kimball Kinnison has attained the goal which every Lensman seeks, and so few attain, that of Unattached Lensman, a Lensman who is accountable to no one anywhere, completely independent, completely free. Further, he is learning how to fully use his lens. This knowledge is crucial, because as he works his way up through the ranks of the enemy the problems are growing more and more complex and dangerous. Coming face-to-face, and mind-to-mind, with the multi-tentacled scaley creature in his corpse-littered domain, Kimball Kinnison must use everything he has learned to defeat the beast or die trying.