Threshold

When the strange fossil she'd discovered gave her a trip to Mars, Helen Sutter thought she'd gone about as far as any paleontologist would ever go in her lifetime. But when you're married to an overconfident super-sensor expert for the only private agency in space ��the Ares Corporation ��and your best friend is a former secret agent for the Interplanetary Research Institute of the United Nations, there's always somewhere farther to go.�

Soon Helen's new discoveries will lead her �to the mysterious asteroid Ceres and beyond in a desperate race to reach Jupiter's perilous miniature system of radiation-bombarded moons. It seems the next gold rush is on��or alien technology.���

And there are people willing to do anything to get it ��even if they must start the Solar System's first interplanetary war!

About the Boundary series:

��A] genial, fast-paced sci-fi espionage thriller [that is] light in tone and hard on science�色����I>Publishers Weekly on Threshold

��P]aleontology, engineering, and space flight, puzzles in linguistics, biology, physics, and evolution further the story, as well as wacky humor, academic rivalries, and even some sweet romances.����I>School Library Journal on Boundary