The third volume in Larry Niven and Edward M. Lerner’s renewed exploration of Known Space shares the virtues of its two precursors, Fleet of Worlds and Juggler of Worlds: fidelity to the style and tone of the original stories, a more richly detailed treatment of the setting, and a fuller exploration of Niven’s central ideas. In contrast to Juggler of Worlds, which largely retold the original stories from a different point of view, this book tells a new story, but one that grows out of previously described events: The wave of supernovae propagating through the Milky Way, and the Protector refugees migrating just ahead of it. The main viewpoint character is once again Sigmund Ausfaller, formerly a professional paranoid in the service of the United Nations, and now a key figure in the government of New Terra, a planet inhabited by human former slaves of the Puppeteers who have gained near independence, with Ausfaller’s help.

Niven has always excelled at writing alien characters; he’s one of science fiction’s masters of John Campbell’s formula, “A being that thinks as well as a human being, but not like a human being.” Here Niven and Lerner give us alien characters with greater depth of motivation. We get insights into the mentalities of Puppeteers, Pak Protectors (technically “human,” but they don’t think like human beings), and the starfish-like Gw’oth, natives of the oceans of an ice-covered moon. Their distinctive qualities are brought out all the more strongly as their interests clash, forcing some of them into uneasy alliances.

The end of the book sees the clash partially resolved, the immediate peril averted...but it clearly leaves room for a sequel. The Pak are not beyond any possibility of coming back for a rematch; the Gw’oth have gained access to new technologies, and might find their interests opposed to those of the Puppeteers; and the alliance between the Puppeteers and New Terra could come under strain. I’m sure that Niven and Lerner mean to come back to this version of Known Space, and I expect to find the return interesting.

The overall theme of the book, and the series, isn’t exactly libertarian, though libertarians will find parts of it sympathetic. But there are some ideas that are very striking. On the one hand, there are the Pak, a hyperintelligent race who can calculate the rationally predictable payoffs of their actions, and have no choice but to pursue it...even if that means betraying an ally; they are the ultimate low-trust society. Axelrod’s concept of the iterated Prisoner’s Dilemma as a situation where honest dealing is rationally self-interested doesn’t apply to them; they always calculate the maximum immediate payoff and go for that. The portrayal of Pak society thus in a way is an exploration of different ways of conceiving of self-interest...and of the limitations of one way.

On the other hand, there are the Gw’oth, a race whose members can link their nervous systems directly together, forming a single living supercomputer. At a key point, a Gw’oth character discusses the social position of such group minds, or Gw’otesht: in low-tech societies, a group entity was hampered, being less able to react quickly and defend itself against threat, and so Gw’oth societies all have taboos against the practice. But those who violate the taboos are able to create new technology, making them a source of wealth and political power, and so rulers who protect them gain victories over other rulers. In a curious way, Niven and Lerner have come up with an allegory of capitalism...an economic system that is based on a more effective mode of cooperation, that creates new technology and new wealth, that makes governments more powerful, but that is often resented by the general population.

I don’t think that Niven and Lerner necessarily consciously intended either of these interpretations. But the fact that they can be found shows the richness of the world they’re developing. It’s a setting that’s worth exploring.