Book III of Skylark series. As the mighty spaceship Skylark roamed the intergalactic space ways, scientist Richard Seaton and his companions found a world of disembodied intelligences. A world of four dimensions where time was insanely distorted and matter obeyed no terrestrial laws…where three-dimensional human intellects had to fight hard to thwart malevolent, invisible mentalities…Cover art by Chris Foss.