Banned from interstellar travel for their aggressiveness, humans have one last chance to regain the stars, provided they can solve the mystery of the disappearance of a pair of alien ships lost somewhere in the unknown part of space known as the Geyser Swirl. This sequel to The Mind Pool continues Sheffield’s far future history of humanity’s attempts to explore the universe. His skill at blending hard science with fast-paced plotting and colorful characters makes this a first-rate SF adventure that belongs in most libraries.