At the close of the 21st century, Lee Vidar is a Starship Industries switch pilot on the Callisto-Europa run. The job is easy: pick up the Orion engines -- used to power our first starships on the voyage to Hope -- ferry them to the run's midpoint, hand off the dangerous cargo and return to Callisto. But today nothing goes to plan, and Lee's sometime lover and old friend Johnny Dujohn is involved.