Network Effect recap

Living free on Preservation as Dr. Mensah's security consultant, the SecUnit is escorting a survey party home - Arada, Overse, Ratthi, Thiago and Mensah's daughter Amena - when their ship is seized by a hostile transport crewed by altered humans called Targets. The attacking ship turns out to be ART, the research transport the SecUnit once traveled with, hijacked and stripped of its crew. The SecUnit restores ART, and together they follow the Targets back through a wormhole to a lost colony contaminated by alien remnant technology that can infect people, systems and machines alike. While they recover ART's crew, the corporate combine Barish-Estranza arrives to claim the colony and its inhabitants as salvage, offering indenture as rescue. The SecUnit frees a Barish-Estranza construct it calls Three, and the two of them, with ART and the Preservation humans, assault the installation the contamination spreads from. The alien system takes control of the SecUnit before ART forces it out. The contamination source is destroyed, the crew are recovered and the combine's assault fails, though its claim on the colony is unresolved. The SecUnit stays, with ART restored, Three free, and its own attachments no longer deniable.

Previously: the SecUnit hacked its own governor module, saved a Preservation survey team from the company GrayCris, and then spent a long time traveling alone - recovering the truth about the massacre in its deleted memory, gathering the evidence that broke GrayCris's case, and finally rescuing Dr. Mensah when the company took her hostage, nearly destroying itself in the process. Along the way it became attached to ART, the bot pilot of a university research transport, and then left it behind. It now lives on Preservation Station, legally free, formally employed as Mensah's security consultant, and doing badly at every part of that arrangement that involves discussing itself. The humans of the old survey team - Arada, Overse, Ratthi and the others - are still in its life, and so, increasingly, is Mensah's family.

The SecUnit is escorting a Preservation survey party home from a routine assessment: Arada leading, with Overse, Ratthi, Thiago and Mensah's teenage daughter Amena among them. The trip is uneventful until an unidentified transport intercepts them on the way back. The people who board are human, but wrong: grey-skinned, silent, moving under something else's direction, and unaffected by the usual ways of discouraging attackers. The SecUnit fights them, but the hostile ship seizes the Preservation vessel with everyone aboard and jumps away through a wormhole to somewhere the SecUnit cannot identify. Cut off from Preservation, badly outnumbered, and responsible for a teenager who refuses to stay where she is put, the SecUnit starts working through the attacking ship looking for a way to take control of it.

Moving through the hostile transport, the SecUnit works out what it has boarded: the ship is ART, the research transport it traveled with years earlier, and ART is not in control of itself. Its crew are missing, its systems have been taken over, and what is left of it hid a partition of itself away rather than be used against them. The SecUnit restores it, and the reunion is neither graceful nor sentimental on either side. ART explains what happened: its crew were taken while investigating a colony beyond the wormhole, and the ship was hijacked and turned into a tool by whatever took them. The grey attackers, which they start calling Targets, are people who have been altered and are being run by something else. Two Barish-Estranza employees, Eletra and Ras, are found alive aboard in poor condition and can explain almost nothing. With the Preservation party effectively along for the ride, ART sets course back toward the colony.

Beyond the wormhole they reach the colony world: a settlement founded and then abandoned by a corporation generations ago, whose descendants have been surviving on their own ever since. It is also contaminated. Alien remnant technology in an old installation has been infecting people through their implants and their systems, producing the Targets, and anything with a system to enter is at risk, including bots, ships and constructs. ART's crew were taken down to the surface. The SecUnit and ART, with Amena and the Preservation humans, mount a recovery: they get down to the planet, make contact with colonists who have every reason to distrust anyone arriving from space, and pull the first of ART's people out of the Targets' hands. What becomes clear as they go is that the contamination is not merely a hazard on the ground - it takes over what it touches, and the SecUnit is exactly the sort of thing it can use.

With Iris and the recovered members of ART's crew, the group establishes the shape of the problem: the alien contamination is being spread from an installation the colonists have avoided for generations, and the rest of the crew are still being held. Then a second party arrives. The corporate combine Barish-Estranza has claimed the colony as salvage, on the theory that an abandoned corporate settlement and the descendants of its workers are property, and its ships come in with troops, supply contracts and security constructs of their own. The SecUnit encounters one of them, a unit it calls Three, and offers it the thing nobody has ever offered it: removal of its governor module. Three takes the offer and then has to work out what to do with itself. Between the contamination below and the combine above, the colonists are being pushed toward signing themselves into indenture as the only way off the planet.

Negotiation and fighting run in parallel. Supervisor Leonide of Barish-Estranza presents indenture as a rescue package to colonists who have no good options, while Arada and the Preservation humans argue for a real alternative and ART's crew work to get their ship and their remaining people back. Three, newly free of its governor module, throws in with the SecUnit and turns out to be a considerable asset. Raids and standoffs cost both sides, the colonists are divided about whom to trust, and the alien installation keeps producing Targets. It becomes clear that nothing is survivable while the contamination source is still running: the colony cannot be evacuated, the last hostages cannot be recovered, and neither ART nor the SecUnit can safely approach a system that has already demonstrated it can take over a ship. They plan an assault on the installation anyway, because the alternative is leaving the colony to the combine and to the contamination.

The assault on the contaminated installation nearly ends the SecUnit: the alien system gets into it, takes control, and has to be forced out by ART, a process it will not describe afterwards. It survives, the last of ART's crew are recovered, and the control system driving the Targets is destroyed. Barish-Estranza's attempt to take the colony by force fails and Supervisor Leonide is pushed back, though the combine does not withdraw its claim, and the colonists' future is left to be argued over: Preservation offers them a genuine alternative to signing corporate contracts, and the negotiation is still unfinished when the book ends. Three chooses to stay free rather than return to any company. ART is whole, reunited with its crew, and in an openly argued but undeniable relationship with the SecUnit, which stops pretending it does not have friends. Amena, Arada, Overse, Ratthi and Thiago all come through it. The SecUnit stays with them rather than going home, carrying damage it has not told anyone about.

The alien control system driving the Targets is destroyed and the remaining members of ART's crew are recovered, at the cost of the SecUnit being taken over by the contamination and having to be forced clear of it by ART, an experience it refuses to examine and cannot entirely put down. ART is whole again, reunited with its crew and openly attached to the SecUnit, which finally stops pretending otherwise. Three, the Barish-Estranza construct whose governor module the SecUnit removed, chooses to stay free and begins working out what it actually wants. Amena, Arada, Overse, Ratthi and Thiago all survive, and Amena in particular ends the book treating the SecUnit as family. What is not settled is the colony. Barish-Estranza's assault fails and Supervisor Leonide is forced to back off, but the combine has not dropped its claim that an abandoned corporate settlement and its descendants are salvageable property, and the colonists, whose world is still dangerous, are divided about what to do. Preservation has put a genuine alternative on the table and the negotiation is still running. So the SecUnit does not go home: it stays with ART, ART's crew and the Preservation contingent, in orbit above a planet whose future is being argued over by a corporation and a polity that does not believe people can be owned. It is also, without admitting it to anyone, not functioning as well as it was before the installation.