An original novel set in the universe of "Star Trek: The Original Series"! The Xondaii system, located in an area of non-aligned space near Federation and Romulan territory, is home to a unique stellar phenomenon: a spatial rift which opens every 2.7 Earth years, remains open for a period of approximately twenty-one Earth days, and allows access to a small planetoid that orbits in proximity to the system's fourth planet. During this brief window, the people of Xondaii undertake a massive interplanetary operation: mineral ore is ferried from the mining operation while supplies, crew replacements, and so on are transported from the planet. Also, communications with the mining colony on the planetoid are possible only when the rift is open. Science vessel U.S.S. "Robert Ballard" is severely damaged during its mission to the system, and the "U.S.S. Enterprise" is dispatched to investigate and render assistance.