Children of the lens [by] E. e. "Doc" Smith

Children of the Lens is the sixth and concluding volume of the six classic Lensman books, long recognized as the greatest space opera ever written. Twenty years have passed since the events portrayed in Second Stage Lensman. To Kimball Kinnison and his wife Clarrissa have been born five children Kit, the eldest, and two sets of twin sisters. These are the 'Children of the Lens' the offspring of uncounted generations of selected matings. The most capable, the most brilliant minds in the universe. Their job is the conclusion of the Boskonian war, and how they accomplish this end and gain ultimate victory makes up the greater part of the book.