Ace Double M-139 Contents: Side A: The Tree Lord of Imeten • artwork by Jack Gaughan; novel by Tom Purdom "Two dare the dangers of the jungle planet" Side B: Empire Star • novel by Samuel R. Delany; interior artwork by Jack Gaughan "He warped time and space to deliver a message to eternity" On a habitable moon near Tau Ceti, a young man named Comet Jo encounters a devil-kitten and sees a spaceship crash land. One of the people in the spaceship tells Jo that he has to take an urgent message to Empire Star, and dies. Another collapses to form Jewel, a compact, multicolored, multiplexed crystalline entity. Empire Star is the story of Comet Jo's journey to deliver the message, as narrated by Jewel.