By Hal K. Wells Benjamin Marlowe and his young assistant, Larry Powell, opened the door of the Marlowe laboratory, then stopped aghast at the sight which greeted their startled eyes. There on the central floor-plate directly in the focus of the big atomic projector stood the slender figure of Joan Marlowe, old Benjamin Marlowe’s niece and Larry Powell’s fiancee. The girl had apparently only been awaiting their return to the laboratory for around her gray laboratory smock was already fastened one