Ex-government agent Frank Compton must halt a murderous plague that threatens to turn the galaxy-spanning Quadrail into a ghost train in the fourth installment of Hugo Awardwinning author Timothy Zahns acclaimed Quadrail series The Chahwyn created the Spiders to keep their intra-galactic transportation system, the Quadrail, safe and running smoothly, and contracted ex-security agent Frank Compton to protect its integrity. So far, Compton and his half-human, half-Chahwyn partner, Bayta, have had their hands full keeping this essential link between occupied worlds open and preventing the evil collective intelligence called the Modhri from using it to spread their mind-controlling infection. But now a new threat has boarded, one that troubles even the Modhri.