Somewhere among the galaxies is the stronghold of Boskone - a network of brilliant space-criminals whose hunger for conquest threatens the continued existence of all known civilisation.

But where is this stronghold? Boskonian bases are scattered across the universe - hidden by gigantic thought-screens that defy penetration. The best minds in the Galactic Patrol have tried. And failed. Now it is up to Lensman Kim Kinnison, using his fantastic powers, to infiltrate the Boskonian strongholds, find the location of the enemy's Grand Base - and smash it forever.

But Kinnison doesn't know that the power of Boskone reaches further than anyone dreamed - into the Galactic Patrol itself . . .

Grey Lensman is the fourth self-contained novel in E. E. 'Doc' Smith's Lensman series, one of the all-time classics of adventurous, galaxy-spanning science fiction.