In 1968, Pyramid Books issued a paperback edition under the title Masters of the Vortex, promoting it as "the final adventure in the famous Lensman series.

The problem is, it takes the best computers available hours to calculate the factors needed, and only seconds are available to get the correct amount of explosives on target.

Devastated by the loss of his family, Cloud takes a leave of absence from the Radiation Lab where he works studying the vortices.

It is slightly technical (Smith explains it so it can be easily followed), but the general idea is that Cloud's brain works so fast that he can calculate exactly where the center of the vortex will be at a moment in time and how big an explosive is needed, then hit it with a bomb that is set at the exact strength to actually extinguish the vortex instead of blowing it apart and making more vortices.

A specially modified, light cruiser (called Vortex Blaster II ) outfitted to carry everything that is needed to extinguish vortices.

Working closely with Joan on a series of ever faster computers, his eyes soon turn more and more toward his pretty, super smart, and self-taught psychic co-worker and his heart begins to heal.

As they fall in love, he bonds psionically with Joan, a pivotal point in the novel, as this leads him to find and communicate with the pure-energy alien beings that have been unknowingly causing the problems.

In the end an agreement is reached, the aliens close down the "incubators" and move their offspring to vortices the Patrol has helped set up on uninhabited planets.

Galaxy reviewer Floyd C. Gale rated the book four stars out of five, stating that "while the modern trend of sf has passed good Doc Smith by" he still got "a huge bang out of this super-duper yarn.