Sylveste is the only man ever to return alive and sane from a Shroud, an enclave in space protected by awesome gravity-warping defenses: "a folding a billion times less severe should have required more energy than was stored in the entire rest-mass of the galaxy." Now an intuition he doesn't understand makes him explore the dead world Resurgam, whose birdlike natives long ago tripped some booby trap that made their own sun erupt in a deadly flare.

Meanwhile, the vast, decaying lightship Nostalgia for Infinity is coming for Sylveste, whose dead father (in AI simulation) could perhaps help the Captain, frozen near absolute zero yet still suffering monstrous transformation by nanotech plague. Most of Infinity's tiny crew have hidden agendas—Khouri the reluctant contract assassin believes she must kill Sylveste to save humanity—and there are two bodiless stowaways, one no longer human and one never human. Shocking truths emerge from bluff, betrayal, and ingenious lies.

The trail leads to a neutron star where an orbiting alien construct has defenses to challenge the Infinity's planet-wrecking superweapons.