The dilithium mining outpost on BorSitu Minor is an understaffed, uninteresting, unspectacular place full of miners, engineers, and scientists who have never done harm to anyone, nor do they have anything of value.

Yet the outpost has been devastated by a brutal assault, with almost all hands lost -- and the survivors have no idea what attacked them. Worse, the attack weapon appears to have the power to penetrate the outpost's powerful shields. That has the crew of the U.S.S. da Vinci worried, as it could just as easily destroy a starship!