London, Mills & Boon, 1922-1923. First Edition. First Impression. Hardback. Near fine copies. In the rare jackets. We were unable to find another copy of Herbert in the jacket (presumed later issue as per Locke I p139). Science fiction adventure set during WWI, the story in Herbert being completed in Prisoner. 16pp ads to both volumes. There's a little toning to the jackets and some chipping to the spine tips, but overall in excellent condition. Prisoner has a vertical crease to the spine. Spine tips bumped, a little offsetting to endpapers, dustiness to the edges. [8640, Hyraxia Books].