In the year 2082, tens of thousands of coordinated comet-like objects of an unknown origin, dubbed "Fireflies", burn up in the Earth's atmosphere in a precise grid, while momentarily broadcasting across an immense portion of the electromagnetic spectrum, catching humanity off guard and alerting it to an undeniable extraterrestrial presence. It is suspected that the entire planet has been surveyed in one effective sweep. Despite the magnitude of this "Firefall", human politics soon return to normal. Soon afterwards, a comet-surveying satellite stumbles across a radio transmission originating from a comet, subsequently named 'Burns-Caulfield'. This tight-beam broadcast is directed to an unknown location and in fact does not intersect the Earth at any point. As this is the first opportunity to learn more about the extraterrestrials, three waves of ships are sent out: the first being lightweight probes shot out for an as-soon-as-possible
flyby of the comet, then a wave of heavier but better-equipped probes, and finally a crewed ship, the
Theseus.
Theseus is propelled by an antimatter reactor and captained by an
artificial intelligence. It carries a crew of five cutting-edge
transhuman hyper-specialists, of whom one is a genetically reincarnated vampire who acts as the nominal mission commander. While the crew is in hibernation en route, the just-arrived second wave of probes commence a compounded radar scan of the subsurface of Burns-Caulfield, but this immediately causes the object to self-destruct.
Theseus is re-routed mid-flight to the new-found destination of the signal: a previously undetected
sub-brown dwarf deep in the
Oort cloud, dubbed 'Big Ben'. The crew wakes from hibernation while the
Theseus closes on Big Ben. They discover a giant, concealed object in the vicinity, and assume it to be a vessel of some kind. As soon as the crew uncloaks the vessel, it immediately hails them over radio and, in a range of languages varying from
English to
Chinese, identifies itself as 'Rorschach'. They determine that Rorschach must have learned human languages by eavesdropping on comm-chatter since its arrival, sometime after the Broadcast Age began. Over the course of a few days many questions and answers are exchanged by both parties. Eventually Susan James, the linguist, determines that 'Rorschach'
does not really understand what either party is actually saying.
Theseus probes Rorschach and finds it to have hollow sections, some with atmosphere, all filled with levels of radiation that render remote operation of machinery virtually impossible and would kill a human in a matter of hours. Despite this and over Rorschach's objections the whole crew except the mission commander enters and explores in a series of short forays, using the ship's advanced medical facilities to recover from the damage the radiation inflicts on their bodies. They discover the presence of highly evasive, fast-moving nine-legged organisms dubbed 'Scramblers'. They kill one and capture two for study. The 'Scramblers' appear to have orders of magnitude more brainpower than human beings but use most of it simply to operate their fantastically complex musculature and sensory organs; they are more akin to something like white blood cells in a human body. They are dependent on the radiation and EM fields of Rorschach for basic biological functions and seem to completely lack
consciousness. The crew explore questions of identity, the nature, utility and interdependence of intelligence and consciousness. They theorize that humanity could be an unusual offshoot of evolution, wasting bodily and economic resources on the self-aware ego which has little value in terms of Darwinian fitness. Open warfare breaks out between the humans and the Scramblers and
Theseus eventually decides to sacrifice itself and its crew using its
antimatter payload to eliminate Rorschach. One crew member, the protagonist and narrator Siri Keeton, is shot off inside an escape vessel in a decades-long fall back to Earth to relay the crucial information amassed back to humanity. As he travels back towards the inner Solar System, he hears radio broadcasts which suggest that the vampires have revolted and may be exterminating baseline humanity. ==Characters==