When a scientific expedition is launched to study a mysterious alien race, the only ship available is the Nightflyer, a fully autonomous vessel manned by a single human. But Captain Royd Eris remains locked away, interacting with his passengers only as a disembodied voice—or a projected hologram no more substantial than a ghost.

Yet that’s not the only reason the ship seems haunted. The team’s telepath, Thale Lasamer, senses another presence aboard the Nightflyer—something dangerous, volatile, and alien. Captain Eris claims to know nothing about the elusive intruder, and when someone, or something, begins killing off the expedition’s members, he’s unable—or unwilling—to stem the bloody tide.

Only Melantha Jhirl, a genetically enhanced outcast with greater strength, stamina, and intelligence than other humans, has a chance of solving the mystery—and stopping the malevolent being that’s wiping out her shipmates.

But first she has to keep herself alive.