The Argian race planted War Temples on every world they conquered, but by Benny's time every one of those temples has been looted. Or so it appeared, until a recent expedition uncovered evidence that it was the Argians themselves who moved the treasures, to the Temple of the Gods of the Underworld on Venedel. Venedel is a feudal, superstitious world which never recovered from the Argians' rule; perhaps they kept the natives at a primitive level so they would never know of the treasures hidden on their world. Braxiatel has offered to send an expedition to Venedel, but there's a problem; the Thane of Mahel stands accused of human rights violations, and the Earthlink Federation has imposed a blockade on Venedel. And yet, while turning down Braxiatel's offer, they have permitted the callous Nishtubi mercenaries through to excavate the temple. Braxiatel asks Benny to lead an expedition through the blockade to learn the truth, and in order to convince her to accept the dangerous mission, he informs her that the Temple may be the location of the Oracle of the Lost. According to legend, the Oracle can pinpoint the location of any living being in the Universe... and if those legends are true, then perhaps Benny can finally learn the whereabouts of Jason Kane.
Benny travels to the Pan Leica spaceport to meet her fellow archaeologists, a human named Shell and the ratlike Waskas Arko and Forno. They need a pilot to get them through the blockade, and the only reasonably qualified applicant is Starl Stanmore -- but moments after hiring him Benny learns that Starl put all of the other pilots out of commission to be sure of getting this job. Pursued by an angry mob of the pilots' friends, Benny and the others must flee to Starl's ship, the New Dawn, which saw better days several centuries ago. Starl gets them away from Pan Leica and navigates a safe route through the minefield around Venedel -- but as they approach the planet they hit a Nishtubi ship running under a cloaking field. The collision draws the attention of the Federation forces, which open fire. Only one of the New Dawn's two escape pods remains, and Shell, Arko and Forno must cram themselves inside and leave Benny and Starl to pilot the New Dawn to safety. Starl lands reasonably safely, but the antigravs fail and he and Benny barely get out before the New Dawn sinks to the bototm of the swamp. They set off in search of the others, but instead stumble across evidence of the Thane's reported crimes -- a pit in which several natives have been burned alive...
Arko is the first to recover from the escapd pod's rough landing, but when he emerges he and his friends are arrested by a Nishtubi warrior. The Nishtubi forces them to lie down by the pod while he searches them for weapons, and then takes them to a meeting with General Maddaska -- but Shell remains unconscious, and Arno notes a strange sticky residue around her mouth. Maddaska turns his captives over to the Thane's chief warrior, Renad, claiming that they have come to steal the food which Maddaska's men smuggled through the blockade. Arko protests their innocence to no avail; the people of Venedel regard non-humanoid aliens as beasts, and intend to eat him and Forno at their feast. Shell, awake but unwell, seizes a gun from the body of a Nishtubi who died in the crash, and Arko and Forno try to hold off the others and escape -- but Shell is too ill to run. Arko and Forno must leave her behind, although Renad claims that she is already dead and must be burnt. Maddaska seems to have taken an interest in her...
Benny, horrified, insists that the Federation must take more positive action to stop this, but Starl points out that if they intervene directly some of their member worlds might protest and secede. She still isn't convinced, but soon gets something else to think about when she and Starl stumble across the Argian temple. To her fury, the Nishtubi have blasted their way in, nearly damaging the hieroglyphics depicting one demon god rising up and imposing its will upon the others. But when she examines the walls more closely, she notes that the facade has been modified with synthetic materials, which the Argians would never have condoned in one of their sacred temples. She and Starl proceed further, but a vision of a demon appears before them in the darkness; whether a hologram, an actual demon or a trap set to protect the temple, they decide the safest course is to flee back outside... where they run straight into the hands of the Nishtubi.
Maddaska leaves two Nishtubi on guard outside the Temple, but as soon as the others have gone, Arno emerges from hiding and stuns them with his stolen weapon. He leaves Forno to keep an eye on them while he follows the others, and Forno spends the time making a preliminary survey of the Temple. He too discovers that it's been modified within the past few centuries, but before he can investigate further, he hears movement and must hide. A creature using a malfunctioning translator walks by, speaking to Maddaska over a communicator; something has caused structural damage to the temple, and Maddaska's ally has learned that the Federation is about to make its move. As Maddaska's ally departs, Forno sees a woman dressed in gauze drift out of the Temple, an ethereal smile on her face... and then hears something far less pleasant approaching from inside and flees.
As the Nishtubi march their captives to a meeting with the Thane, Benny and Starl realise that the Nishtubi are misleading the natives about the worth of the artefacts in the tomb in order to keep the profits for themselves. The Thane won't listen to them, however; accusing them of starving his people to death with the blockade, he throws them both into the cells. He, Renad, and the court scribe Hoodath attend the celebratory feast, along with Maddaska, who politely turns down the Thane's offer of food. Meanwhile, Benny and Starl trick their guard and escape, and discover a room full of junked Federation equipment -- including a functioning telex which is still printing out ignored communiqués from the Federation, warning the Thane that if their demands are ignored they will launch a nuclear strike on Mahel. Benny and Starl rescue two other Federation prisoners, civil servant Dex Tinhar and freelance journalist Han Krista, who explain that Venedel is being swept by a plague -- but the Thane is burning down the forests and torching the victims alive, rather than seeking a cure.
Before Benny can learn more, the natives discover that they have escaped and recapture them. This time the Thane has had enough; aliens will never make his people pay again. Benny and her allies are thrown into a pit, along with Shell and the other plague victims, and the natives prepare to burn them alive. But the flamethrowers provided by the Nishtubi don't work, and as Benny watches in horror, lizard creatures burst out of the infected bodies in which they have been incubating. As the Venedelans begin to panic, the Nishtubi unexpectedly grab three of the infected natives and flee into the woods, shooting anybody who tries to follow them. Arko, who has been watching from a distance, takes advantage of the confusion to burrow into the pit and try to rescue his friends, but the floor of the makeshift burrow gives way, dropping Benny, Shell and Tinhar into an underground tunnel which Arko didn't realise was there. As Renad begins to fill in the pit to prevent the lizard Ilijah from escaping, Arko, Han and Starl flee back into the swamp -- where they see the Nishtubi killing the infected natives and removing the mature Ilijah from their bodies. This is what they were here for all along.
Benny and Shell awaken to find that Tinhar has left them for dead inside the ventilation system of an underground structure. The structure is falling apart around them, and as they try to find a way out Shell falls through an unstable section and is lost. Benny continues on and finds Tinhar, who claims that he doesn't know what this place is; however, Benny finds a plaque on the wall, stating that this is the property of the Earthlink Federation. Tinhar also seems to know more than he should about the Ilijah, and when Benny pushes him he explains that they are a genetically engineered weapon used by the Nishtubi's former employers, the Boor. The Boor once operated an interplanetary extortion racket, releasing the voracious Ilijah upon a planet and selling the immunisation serum for a price; however, the racket was crushed by the stellar police some five centuries ago. Further explanations are curtailed by the continuing collapse of the structure; whatever it is, some disaster has weakened it. Benny kicks her way through a weakened wall panel, and on the other side, she and Tinhar find themselves inside a corridor of the original Argian temple. Unfortunately, these tunnels were usually sealed off when work was complete...
The next morning, as Arko, Starl and Han return to rescue their friends, Starl notices that the water level in the swamp has gone down considerably. They are forced to withdraw from the pit when they are attacked by an Ilijah, which appears much larger than it should be at this stage of its life cycle. The Ilijah's eggs are contained in its spittle, and though Arko, Starl and Han escape, the eggs float away on the wind -- which explains how Shell became infected after lying in the swamp. They return to the temple, where they are reunited with Forno and meet the nubile woman from the temple, who collapses in Starl's arms. Starl examines the unconscious woman and finds a catheter implant in her wrist, evidence of invasive surgery which has been obsolete for centuries. Meanwhile, Arko and Forno nearly fall into an animal pit with spikes at the bottom -- and are then attacked by two dark-skinned creatures, dressed in the same gauze and sporting the same implants as the woman from the temple.
In the face of the disaster the Thane's people have fallen into despair. Renad does not know which way to turn; should he pray to the gods or demand answers from the Nishtubi? He decides on the latter, and gets more answers than he bargained for when he overhears a conversation between Maddaska and his mysterious ally -- High Boor Bantagel. After the fall of the Boor, the Nishtubi became odd-job mercenaries for the Earthlink Federation, but Maddaska has always dreamed of restoring their glory days. Thus, he hired bioengineers to recreate the Ilijah in secret, and used Venedel as a testing ground, doping the smuggled grain in order to make the people better carriers. Now he has collected samples of the new-breed Ilijah and has woken Bantagel from his cryogenic sleep in order to synthesise a new cure; soon, they will be back to their old tricks, but this time, as equal partners. Enraged, Renad returns to his people and tells them of the Nishtubi's treachery. The Thane gives him free rein to whip up the people into a frenzy of revenge -- but as they prepare to set off and do battle, the Ilijah burst out of the swamp. Only a few of the natives escape; many others, including the Thane, are killed.
Benny and Tinhar dig their way out of the Argian tunnel, and emerge in the animal pit -- just as their struggling friends throw in the attacking aliens. The terrified Tinhar recognises the aliens as members of the Shik triads and tries to flee, but one of the Shik kills him. Benny manages to knock them out and escape from the pit, and she and the others flee into the forest, forced to ignore Han's insistence that they return for Tinhar's body. They find that in their absence, the woman from the temple has woken; she is Janrees, the Overseer of Obvion, a planet laid waste by the Ilijah five centuries ago. The fledgling Federation had promised to resettle her people on a new world, but now it appears that they simply abandoned the Obvions in their cryogenics storage facility. Five centuries ago, the Federation was still trying to make a name for itself; the Feds needed easy answers and a quick reputation, and they simply shuffled all of their problems off on Venedel and tried to forget about them. The blockade has little to do with the Thane's actions; the Federation is simply trying to keep its past from coming to light. But now something has wrong with the cryogenics facility, causing its structure to fall apart and waking Janrees and the Shik from stasis.
As Benny and the others discuss these events, they realise that Han is nowhere to be seen; she has ditched them and fled into the forest to broadcast a warning to her paymasters that their secrets are about to be revealed. Her paymasters in turn warn her to leave immediately, for they are rigging the results of a Federation referendum; within hours there will be a nuclear strike on Mahel. Han returns to the pit to search Tinhar's body, only to find that the Shik have already done so and taken the recall device. She follows their trail back to the temple, but Benny and the others follow her and arrive just in time to see the Shik using the stolen recall device to phase Tinhar's escape shuttle back into normal space. Janrees and Han try to stop the Shik from stealing the ship, but they fail; however, when the Shik try to take off, it explodes, proof that Han and Tinhar were never meant to leave the planet alive. Starl accuses Han of being an agent of the so-called Shadow Federation... and Benny finally realises that Starl is also a secret agent, who infiltrated her expedition in order to get to Venedel without raising suspicion.
The Nishtubi arrive, but so do the Ilijah, and in the confusion Benny and the others escape into the temple. Benny reconsiders the pictograms in the light of what they've learned, and realises that they're an in-joke; they depict not the gods of the Argian underworld, but the "gods", or kingpins, of the Federation's criminal underworld. And the demon who bested his fellows is a Boor. Starl admits that the Federation has been corrupt since the beginning, and that the Boor gathered enough evidence to blackmail the "Shadow" Feds and strike a deal with them. The Boor and the Shadow Federation joined forces to put the Boor's rivals on ice; the Boor themselves would lay low for a while, and then awaken the other kingpins individually and force them to swear allegiance to the Boor, uniting all the gangs into a single super-criminal empire. But the Shadow Federation reneged on the deal and left them in stasis for centuries... until Maddaska discovered the truth, and woke up Bantagel to start the Ilijah racket. However, it appears that something is going wrong with the cryogenics facility, which is why Janrees and the Shik awoke... but it now occurs to Benny to wonder why Janrees was in a cryogenics facility for criminals. Han finally gets the chance to inform them that Janrees is the leader of one of the most notorious criminal syndicates in history -- and she's vanished, taking Forno with her.
As the Nishtubi pursue the intruders, an Ilijah suddenly hatches out of one of them; apparently the bioengineering worked too well, and not even the Nishtubi are immune to this new breed. Maddaska sends his men on ahead while he confronts Bantagel, demanding a cure. But Bantagel is used to being in a position of power, and he has been concentrating on finding cures only for the species which can afford to pay him. He has already awoken his own people, but as far as the other gangs are concerned, he intends to rescue only the kingpins and leave the others to die in the Federation bombardment; there's clearly something very wrong with the underground facility. Meanwhile, the surviving Venedelans arrive at the Nishtubi ship only to find it apparently abandoned. The frustrated Renad turns on Hoodath, whose insistence on rational thinking flies in the face of Renad's religious fervour, and tears Hoodath's official history to pieces. Believing that the earth tremors are signs from the gods, Renad then leads his people to the temple, leaving Hoodath sobbing over the remains of his life's work.
Han now knows that her paymasters intended to kill her to eliminate a loose end, and agrees to give evidence against them. Starl reveals that he dropped a communications satellite in the New Dawn's second escape pod when they first entered the system; if he steals the Nishtubi ship he can get close enough to send a message to his superiors, and stop the nuclear strike. Benny refuses to leave without Forno, and she and Arko thus set off deeper into the temple and the cryogenic facility beneath. While searching, they find the Shik cryogenic chamber -- and see Shell hanging in mid-air, having fallen through the ducting to become suspended in the same time-stasis field which the Federation used to freeze the gangsters. This part of the facility is flooded with foul-smelling water, and when Benny and Arko explore further they finally learn why everything is falling apart. When the New Dawn crashed in the swamp, it crashed on top of the cryogenics facility, and the swamp drained away into the systems, short-circuiting them. By now the entire swamp has drained away... and as Benny and Arko watch, hordes of Ilijah pour through the breach in the facility.
Janrees has taken the smell-sensitive Forno to warn her of pursuit while she attempts to wake her people. Desperately trying to stay in her good books, Forno studies the cryogenics units and suggests that Janrees must have been woken by a power surge; perhaps by triggering another she can wake the other Obvions. Janrees does so without waiting to hear the possible dangers, and thus wakes her people -- and shorts out the stasis field in the Shik chamber as well, thus freeing Shell. Benny and Forno carry Shell out of the chamber with them as the Ilijah enter and begin to chew their way through the still comatose Shik. Meanwhile, Bantagel completes his work on the cure for humans, only to learn that the Boor escape ship in the facility has been put out of action by the New Dawn crashing on top of it. They're going to have to use the Nishtubi ship to get away, and Bantagel and Maddaska return to the deteriorating facility to wake the other criminal kingpins.
Renad and his men encounter hordes of Ilijah outside the temple, and as they fight their way past, Starl and Han use the distraction to escape to the Nishtubi ship. There, Hoodath helps them to distract the guards and get on board, on the condition that they take the remains of his manuscript and piece it back together. Unfortunately, in their rush to escape they forget it behind them, and Hoodath watches in horror as it is incinerated by the launch. Meanwhile, the Nishtubi in the temple, still searching for Benny and her friends, apparently encounter the projection which Benny and Starl had seen earlier, a projection which the Nishtubi had left to discourage the natives... or so they think until it begins to incinerate them with beams from its eyes. This is a real Argian defense hologram, apparently activated by all of the commotion in the temple, and it attacks Nishtubi and natives alike, killing them indiscriminately as they flee in terror.
The Obvion women awaken, but the stasis drugs in their system have left them disoriented and giddy, just as Janrees was when she first woke. Bantagel, Maddaska and the Boor arrive, but so do the Ilijah -- who have grown large enough to pose a physical threat to the Boor. Bantagel, infuriated, shoots and kills Maddaska, but as the Boor and Obvions flee they encounter Benny and Arko, who warn them that another pack of Ilijah is coming from the opposite direction. As Janrees and Bantagel argue, Bantagel reveals that he has a cure for the infection, and Benny forces him to give it to Shell. As Starl has already stolen the Nishtubi ship, their only hope is to seek shelter from the bombardment in the deepest levels of the temple. They must pass through a cryo-chamber whose inhabitants were all killed by the power surge Janrees triggered, and once they get to the control chamber Bantagel tries to reactivate the cryo-stasis field to trap the pursuing Ilijah. However, the chamber was flooded when the stasis field went down, and when the power surge hits the water a new wave of short-circuits and explosions rip the floor open to expose the Argian temple beneath.
Three more Argian Gods ascend from the temple, holograms programmed to protect the Argian war treasures, and as they open fire on the intruders, a wild shot breaks open a bulkhead -- and the Ilijah enter before Bantagel is ready for them. As the others flee to safety, Benny lags behind, trying to catch a glimpse of the Oracle of the Lost -- but just as it seems that she's about to get an answer to her question, the exploding cryogenics facilities crash into the temple, destroying the Oracle. Emotionally shaken, Benny nevertheless flees to safety just as Bantagel reactivates the cryo-stasis field, freezing the Ilijah. The Gods also vanish, their programme moot now that the treasures they were meant to protect have been destroyed. The Boor and Obvions head back out into the cryogenic chambers, celebrating victory -- but Benny, her friends and the Venedelans remain in the control chamber, and before Bantagel realises what they're doing, Forno operates a second set of controls, freezing the Boor and Obvions as well.
In desperation, Starl attacks the Federation fleet, single-handedly confusing them and holding them off long enough for word to get to his superiors and back. At the very last moment, the fleet is told to call off the nuclear strike. With Han to provide evidence, the Federation can start cutting the corruption out of its heart, and they will use Bantagel's cure to destroy the Ilijah infection on Venedel as well. Renad now knows that some aliens can be trusted, just as Hoodath has learned that some can't; they have reached a middle ground, and make peace with other, agreeing to work together for their people. On behalf of the Federation, Starl grants the Braxiatel Collection the right to excavate the Argian temple, once the Shadow Federation's mess has been cleared out of it. Now Benny just has to deal with the angry Pan Leica pilots whom Starl put out of action...