Decades after a successful invasion of Earth and the Terran Democratic Empire by the Ryqril—hostile, leathery-skinned aliens—resistance fighter Allen Caine is training for an undercover mission. He will assume the identity of an aide to the senate—part of the government that colludes with the invaders.

En route to far-off stars, Toby’s consciousness has a crucial mission: inhabit his clone long enough to repair a spaceship, then zip back to Earth. He’s done it a million times, more or less. OK, twelve times. It should only take a few hours. Until he wakes up in jail. And he’s not alone. His fellow prisoners: a cadre of alien soldiers. His prison: an ethereal boundary that will imprison their spirits until their bodies die. His jailers can’t even see him. But their pet cat (er, iguana cat?) can—and it’s got a serious case of the zoomies.

The universe is a dangerous place, a fact violently brought home to Frank Compton for perhaps the thousandth time when a stranger delivering a message dies right in front of him. An operative for Western Alliance Intelligence until his whistle-blowing activities got him fired, Compton is now being sought out by the Spiders, the robotic alien beings responsible for the upkeep and operation of the Quadrail transportation system, which connects the galaxy's twelve inhabited empires.

Only the recently dead can helm the "deadman switch" to pilot a ship through the Cloud, a mysterious solar entity that shields the Solitaire solar system and its valuable heavy metals. Two convicted murderers are routinely sacrificed for this task—one to enter the system, one to exit.

Grad student Danae Panya's dream assignment has been approved. She'll study Triplet, the strange planetary system scarred by nuclear war and connected through portals. The most experienced Courier of Triplet, Ravagin, will lead her to its hidden worlds—Threshold, Shamsheer, and Karyx—and introduce her to their secrets, including their advanced technology, their dark magic, and the captivating demon culture of the innermost planet.