Masters of The Vortex - Lensman Series Book 7

Description from the back of the book

A churning nuclear vortex, appearing out of nowhere, wreaking utter destruction - and countless numbers of them were menacing planets throughout the galaxy! 'Storm' Cloud, nucleonic genius, set out in his spaceship Vortext Blaster to track and destroy the mysterious vortices - and embarked on a saga of discovery and conflict among the far stars and the worlds of the Lensmen...

Condition - Very good, signs of wear on the spine and marks on the cover. Pages yellowing with age.