These are strange days on the planet Halstad; there has been a theft from the city museum, and Jamara’s lover Hulver has vanished. As she searches for him outside the city, she finds her friend Jan instead, but as they discuss recent events there is a sound like thunder in a clear sky and the ground begins to quake. Jan and Jamara try to shelter in the nearby caves, but there is nowhere on the entire planet where they can run...

Years later, Benny is trying to catch up on her rest after taking an economy-class ship to an excavation on a planet of mud, but her sleep is interrupted; first by an overenthusiastic young student, and then by Braxiatel, who arrives in his personal shuttle to ask a favour of her. The auction house at Pelastrodon has a Halstad Harp listed in their catalogue, and Benny is Irving’s foremost authority on the people of Halstad. Seven years ago, the planet’s 20,000-year-old civilisation was destroyed by a burst of cosmic radiation which seared the planet’s surface down to the bedrock; however, the harp in the Pelastrodon catalogue appears to match the description given by one of the few explorers to visit Halstad before its destruction. As such, it’s unique and therefore priceless -- if geniune. Benny agrees to accompany Braxiatel to the auction to verify whether the Harp is indeed the real thing.

The auction house is located near the main trade routes, not far from its rich clients but away from prying eyes. Braxiatel assures Benny that this is all entirely legal, but advises her to be cautious; if they show that they want the Harp, then the auctioneers will double the reserve price and the other bidders will take more of an interest. Braxiatel also wants to explore the possibility that the Harp’s owner may have more memorabilia from Halstad, but Benny warns him to be alert for a possible con; even if the Harp is geniune, the owner might use it as bait to sting Braxiatel into buying more artefacts which turn out to be forgeries. Benny and Braxiatel enter the auction house, where chief auctioneer Davon welcomes them to the Extinction Event -- a special auction in which every item comes from a civilisation which died out suddenly...

Benny browses through the auction’s lots, and irritates Davon by pointing out an attribution error on a Martian War Drum; the label identifies it as being from the wrong period, and that means it’s not as valuable as its reserve price suggests. Benny and Braxiatel also look at the Halstad Harp, and Benny confirms that it’s genuine. It has little intrinsic value, but the rarity more than makes up for it; just as a tiny error can increase the value of a stamp by millions, this harp represents all that remains of an entire planetary civilisation, and is thus worth far more than it would ever have been worth on Halstad itself.

Benny sneaks a look at the bidding record on the Harp, and finds that someone has been checking it every half-hour. Presumably this is the vendor, and Braxiatel thus asks Benny to contact them and find out if they have anything else of value. Benny visits the chambers in question, but bumps into a man coming out -- a man who reacts to her voice, mistaking her for someone called Jamara. He flees, and Benny enters the room to find an alien being writhing in agony in its life support system. She calls Braxiatel, who arrives just in time to save the alien from the radiation weapon which was killing it slowly and painfully. Davon identifies the alien as the Gulfrarg Ambassador, one of the few species to evolve without a skeletal structure or an epidermis. It appears that the person Benny saw leaving the chambers tried to kill him, but why? Benny didn’t recognise him, but he seemed to mistake her for someone else. As she leaves with Davon to make her statement, Braxiatel speaks with the Ambassador; as he can speak the Gulfrarg language, he takes the opportunity to strike a private deal with the Ambassador, to purchase the Harp directly without the indignity of an auction.

According to Davon, the Ambassador is one of the auction house’s most valued customers, and over half of the objects for sale at the Extinction Event belong to him. The Gulfrargs are apparently avid collectors of beauty, though they are offensive both in manner and appearance, and their language consists largely of expletives. Davon takes the radiation weapon to her security teams for analysis, but it appears that the killer will remain unidentified -- until Benny happens to bump into him in the crowd. She chases him to a quiet corner, where he nearly breaks down as she speaks to him; her voice is similar to that of his dead lover, Jamara. As he speaks, Benny realises that he is from Halstad. Hulver was one of only six survivors; three others died, and two killed themselves when they realised what had happened to their home. But before he can explain further, Davon and the security guards arrive, stun him, and find the control box for the radiation weapon on his person.

This seems to be a simple case; Hulver will be locked up until the Gulfrargs can arrange his extradition and execution. But Benny has some questions she wants answered, and Davon thus reluctantly allows her to speak to Hulver. Hulver claims that the Gulfrargs teleported three men and three women from Halstad, conducted cruel vivisectional experiments upon them just for the fun of it, and then forced them to watch as they destroyed the planet. Hulver breaks down in tears as he tells his story, but Davon points out that he has no proof of his claims. The Gulfrargs had no reason to destroy his world; it has no strategic value, no minerals they can’t find elsewhere, and its environment was too hostile to them for colonisation purposes. Hulver admits that he doesn’t know why this happened; all he knows is that the Ambassador is the one who gave the order to destroy Halstad. Hulver barely escaped from the Gulfrargs himself, when their ship docked with a human vessel to trade for supplies -- and when he learned that the monster who had killed his world was here to sell artefacts from Halstad for an obscene amount of money, he came here seeking revenge.

Benny, for one, believes Hulver’s claims, but Davon doesn’t intend to get involved in politics, even if those involve claims of genocide. As far as she’s concerned, Hulver tried to murder a respected customer in a particularly brutal fashion, without proof of his claims. Benny storms off to speak to Braxiatel, only to find that he has just bought the Harp and is now negotiating with the Ambassador to purchase other artefacts from Halstad. Intervening on Hulver’s behalf would sour the deal; they can’t change the past, and if they step wrong now they will lose the chance to preserve Halstad’s memory. Hulver will be extradited to the Gulfrarg homeworld, to be cubed to death. Benny is furious, and points out that the fact the Gulfrarg Ambassador has a Halstad harp is damning in itself; looking as they do, the Gulfrargs can hardly have walked amongst the population as the human explorers did. But with no evidence of wrong-doing and no apparent motive for Halstad’s destruction, there’s nothing that Braxiatel can do, until Benny realises the implications of the fact that the Ambassador can’t have acquired the Harp from Halstad legally. If he can’t prove ownership of the Harp, then legally it becomes the property of the former owners or their heirs. Thus Hulver may be the Harp’s legitimate owner.

Benny and Braxiatel discuss the situation with Hulver, and then confront the Ambassador and Davon. Hulver has identified the Harp as the very musical instrument he was carrying when he was abducted by the Gulfrargs; furthermore, many of the items in the Ambassador’s collection were stolen from a museum on Halstad shortly before the planet’s destruction. The stolen goods vanished as if into thin air... as if teleported out with technology which the Halstads didn’t possess, but the Gulfrargs do. Benny and Braxiatel have to restrain Hulver from attacking the Ambassador again, but they’ve proved their point; since the Ambassador can’t prove ownership of the Harp, the legal position is clear. The artefacts from Halstad belong to Hulver, and if Braxiatel chooses to purchase them from him, Hulver will be able to afford lawyers to contest his extradition. The result will be a costly, public and extended legal battle, unless the Ambassador agrees to accept the payment Braxiatel had originally offered for the Harp to drop the charges. The Ambassador is enraged, but has little choice but to accept the offer.

Hulver is free, and he can tell Braxiatel all about the history of his civilisation, preserving his people’s memory. But Hulver isn’t happy about the way events have turned out, and neither is Benny. Hulver remains confined to quarters while Benny attends dinner with Braxiatel and Davon, but she soon storms out, disgusted by the mercenary attitude which Davon hides behind her claims of detachment. All Davon really cares about is the money. Benny returns to speak with Hulver, and tries to help him come to terms with his loss. Benny has lost friends and family in the galactic wars, and the planet she grew up on was destroyed; but she tries to live for the future, not dwell in the past. But Hulver can’t put the past behind him, not when the creature who destroyed his world is going to get away with it.

A security guard suddenly bursts in to arrest them both, but Hulver makes a break for it and escapes. It appears that another attempt has been made on the Ambassador’s life, and Benny is now a prime suspect as well due to her connection with Hulver. As far as Davon is concerned, the Gulfrargs are far more respectable than Benny, who is at best undistinguished and who came here in the company of a man who bypassed the rightful auction system, thus depriving Davon of her commission. As long as Hulver remains at large, Benny will serve as a suitable scapegoat; Davon will allow the Gulfrargs to extradite her, and things will return to normal. Braxiatel posts bail, but he’s furious with Benny for jeopardising his deal; though not as furious as Benny is with him, for forgiving an act of genocide and putting the purchase of the Harp above the lives of the people of Halstad. Braxiatel takes a different view; he’s trying to preserve the memory of Halstad by saving the Harp, and as for the Ambassador’s alleged crimes, they have only the word of a fanatic who tried to kill him in the most agonising manner possible. The Harp is missing as well; it vanished shortly after Hulver fled. Braxiatel and Benny split up to search for him, knowing that they’ll probably find him looking for the Ambassador again...

Davon and the Ambassador are in the observation dome, looking out over the tundra, secure in their belief that all the loose ends have been wrapped up. They have framed Benny and Hulver for a false attempt on the Ambassador’s life, and have recovered the Harp; the auction will proceed as planned. But as Davon tries to laugh off the Ambassador’s inappropriate advances, Hulver arrives, with a gun he took from a guard who won’t be needing it any more. Benny tracks him down just as the Ambassador starts to speak their language; he could have done so all along but couldn’t be bothered. He gleefully admits to destroying Halstad, and claims that Davon knew about it all along. The sickened Benny finally realises the truth; the Ambassador is an art collector, and the value of a piece increases due to its rarity. The artefacts up for sale at the Extinction Event have little intrinsic value; they are only precious because they are the last surviving relics of their civilisations. The Ambassador destroyed Halstad, just to increase the value of the stolen Harp -- and for the fun of it. Enraged, Hulver opens fire, killing Davon and shattering the observation dome; the Ambassador’s force field protects him at first, but it wears down just as Hulver’s gun runs out of power. Benny begs Hulver to turn the Ambassador in and seek justice, but Hulver doesn’t listen, and she can’t stop him from seizing the Ambassador and throwing him out of the observation dome to his death.