Rimrunners is a science fiction novel by American writer C. J. Cherryh, set in her Alliance-Union universe, in which humanity has split into three major power blocs: Union, the Merchanter's Alliance and Earth.

Her luck begins to run out when her latest ship, the freighter Ernestine, is forced to return to Pell for major repairs, a destination too fraught with danger for her.

With time running out before his body is discovered, she signs up with the ship Loki, a barely legitimate 'spook' that survives by gathering intelligence and selling it.

She becomes friends with Musa, a universally respected crewman who claims to have served on one of the ancient sublighters, the original nine vessels that predated faster-than-light ships.

The Mazianni ship had been harried and hunted by Alliance and Union forces to the point that it was blocked from its regular supply bases and is desperately low on fuel.