To escape capture by his detective adversary Narr-Tem, criminal Chun Brun has fled from Uth to Earth. Narr-Tem tracks him down anyway, but must convince him that the "Earth" he fled to is not in another dimension, but is actually the far past of Uth, and any alteration he makes of the timeline could lead to destruction.; Keith Kelvin must prove he isn't a menace to the universe and is really using giant space harpoons to try to capture a giant Ultra-Hawk which entered our universe through a space warp.; The first Earthman envoy to Mars is asked to bring 3 gifts. A rubber ball, a sweet-smelling rose, and a copy of the Mona Lisa. But, why?