Iron Sunrise is a hard science fiction novel by author Charles Stross, which is set in the same universe as Singularity Sky.

In Singularity Sky we are introduced to a universe where human societies have been involuntarily taken from Earth and widely distributed, seemingly at random, across the galaxy in the aftermath of an information singularity. The events in Singularity Sky and Iron Sunrise take place consecutively some time after the immediate aftermath of the singularity.

Martin Springfield and Rachel Mansour return to Earth to recuperate following the events of Singularity Sky. Shortly thereafter Rachel finds herself negotiating with a man with hygiene issues and an armed nuclear device, but only after having to please explain the administrative expenses she incurred during the events of Singularity Sky.

Meanwhile, a young and hopeful civilization is murdered by the apparent use of a casuality violation device which explodes their sun without warning, and its defense systems are automatically deployed against the world of the suspected perpetrators of the atrocity.

Rachel and Martin set off to prevent the assassination of the remaining members of the murdered civilization's leaders who can override the defense systems' controls and to uncover the real power driving these events. The Eschaton continues to play its own game, as always.

See also relativistic kill vehicle