Gray Lensman begins where Galactic Patrol ends, and focusses on Kimball Kinnison's attack on Boskone via the zwilniks. It begins with the discovery that Helmuth's Grand Base was not Boskone's headquarters, but only a fleet base for the First (Milky Way) Galaxy, and that Helmuth's superiors were in fact in the Second Galaxy (Lundmark's Nebula). Taking the Dauntless, our hero heads for the Second Galaxy and discovers that the Second Galaxy is under Boskone's thumb.
Returning home, with the planet Medon in tow, Kinnison calls for a scientific conference which produces the Negasphere. He then decides to try and trace Boskone by following the drug trade, ultimately becoming the meteor miner Wild Bill Williams. Following the hierarchy of drug lords, he finds the base in the First Galaxy, and follows a lead there to the home planet of the Eich, the nine most powerful of whom form the Council of Boskone. In the process he is discovered and tortured, but is rescued by Worsel after leaving a false trail with the Eich.
Returning again to Prime Base on Tellus, Kinnison leads the entire Patrol against the Milky Way drug headquarters, destroying it with a Negasphere of planetary anti-mass, and from thence to the Second Galaxy, where the home planet of the Eich is destroyed by hitting it with two rogue planets, brought into place with planet size Bergenholms. Thus passed the Council of Boskone, leaving Kinnison free to settle down with the lovely Clarissa MacDougal.
The End. Or Is It?