the kind of classic fifties-era first-contact story that Jonathan Swift might have written, if Jonathan Swift had had a background in game theory. In the first installment we encounter an alien race whose peaceful, scientific, and undeniably moral civilization is predicated upon the eating of babies. Our earnest crew wrestles with the intuitive proposition that baby-eating is wrong, but has a much more difficult time than you might think expressing just why that might be. Then we get into the use of tentacle porn as a handshaking protocol. It goes from there.
The remarkable thing about this series (so far, anyway) is that while an almost Douglas-Adamsesque sense of absurdity hangs over the proceedings, the author wrote the story “to illustrate some points on naturalistic metaethics and diverse other issues of rational conduct.” The Prisoner’s dilemma shows up almost at the first paragraph; Bayes’ Theorem is not far behind. And the fact that Yudkowsky’s aliens, biologically, are radically cool in their own right— no wrinkly-headed sock puppets here (and trust me, I know cool aliens when I see them) — is pure bonus.
If you’re at all interested in science fiction, rationality, or the nature of morality, do yourself a favour and read it.