21 - Children of the Lens by E. E. Smith

Earth faces a dire threat once more! The Eddorians have crafted their own version of The Lens and are using hyperspace tubes to launch an invasion with their formidable Black Lensmen. In this climactic showdown, Kimball Kinnison and Clarissa McDougall‚As five extraordinary children, known as The Children of the Lens, must harness their enhanced powers to thwart the impending attack from Eddore. As the final installment in the epic Lensman series, prepare for a thrilling adventure that will keep you on the edge of your seat! - Summary by The Narrator