This novella is a companion to McDonald's Luna books, and I don't think it is an easy entry point if you haven't read at least one of those. It's a teen book, or at least written from a teen viewpoint. It obviously takes its title from Heinlein's "Menace from Earth" but this is not a romance, at least it doesn't end up as one.

So, instead of a cute young thing from Earth coming to the moon and getting all the attention of the main character's boyfriend, a cute young thing (Sidibe) comes from the far side of the moon to the sunlit side and is about to become a sibling of the main character and all of her other siblings. Cariad's parents are in a ring marriage, which is a complicated family system that involves half siblings, step-siblings, and part of Cariad's problem is probably because she hasn't been consulted in any of this.

Cariad also bosses around her current siblings and she recognizes another queen bee when she sees her. Her solution to this upending of the current sibling power structure is to enlist her current siblings (Jair, who identifies as a neko, a cat, and Kobe, who is neuro-atypical in some way) along with Sidibe to go to the original moon landing site and get a commemorative picture for the parents' wedding. They will do this on the sneak, hitching rides on cargo buggies on the moon's surface, using a "borrowed" card to pay for the necessaries along the way, and hacking their way into where they aren't normally allowed. Cariad will be the boss of this journey, and hopes to come out of it covered in glory as the sibs' undisputed leader, and maybe make her new sister look a little less cute in the process.

Cariad is kind of a jerk. The adventure goes sideways, as of course it would, and she doesn't always rise to the occasion of being a leader. She does get her siblings to bond, though, even with herself although she puts them in danger several times. In the end, I'm not sure that Cariad has learned anything from this experience, and I didn't really like her much. That's why I'm not rating the book higher. It's a solid adventure story, though- maybe like one of Heinlein's.

Ian McDonald's LUNA series has led me on something of a dunebuggy ride full of grit and feelings and queerness since it first incepted my brain in 2015 with its initial installment, LUNA: NEW MOON. I found that book tantalizing in the extreme, with some seriously great sentence-work and some great characterization, as well as some good hints at McDonald's evolution in inclusion of LGBTQIA+ characters. It wasn't all the way *there* in some ways, but it primed my appetite for its sequel, LUNA: WOLF MOON, which ramped up both the pace and the representational work and which had me wringing my hands for the third and final installment, LUNA: MOON RISING—which ultimately turned out to be much more of a mess than its predecessor and also somewhat problematic on a couple of fronts. All that is to say, I've had a lot of feelings about this series, mostly good, but mixed enough I never know what to expect.

THE MENACE FROM FARSIDE is a prequel to the LUNA series, a novella set far enough in advance of those others that the Suns' Pavilion of Eternal Light is still but a gleam in the eye of its designers. (The Pavilion plays a key role in the plot of LUNA: MOON RISING and therefore the series' conclusion.) As with the other books in the series, McDonald delves into the complicated politics involved in interpersonal relationships among people building a new society from scratch, and in this case with something I haven't really seen before: ring marriages, i.e. a tortuously knotted web of polyamorous relationships built around iz-derecho bonds. Each person has one each, and I can only think of them the way I think of the color wheel: there's always a color on the left and the right of you, and there's a certain science to what each means to the other. Because THE MENACE FROM FARSIDE follows a set of four teenagers, however, and is told in the narrated voice of one specific teen (Cariad Corcoran), the rules aren't always spelled out. They're not her main focus, save for how a shift in her mother's derecho relationship brings a new sibling into the ring. The relationship is stepsibling=approximate in its nature, defined by the threat of destabilizing existing family bonds and traditions and spaces, as well as by a yearning for belonging. Sidibe, Cariad's new sibling, also comes off as something of a know-it-all showoff who is as envy-inducing as she is annoying. The other two teens along for this particular adventure are also siblings, sort of, and include the neurodivergent Kobe and Jair, a neko. As someone who identifies as nonbinary, I find the introduction of nekos (people who identify as cats?) is a bit strange because it clearly falls somewhere in the general range of queer or queer-adjacent identities, but it also isn't fully spelled out so I'm not sure what all is going on there. But hey, I'm not NOT a fan of the idea. I'm willing to roll with the fuzzy worldbuilding simply because I've already relaxed into McDonald's voice. I'm also ... not a believer in the idea that a novel has to spell everything out in order to qualify as "hard" science fiction. (The underlying assumption seems to be that "hard" = "better" and I hate that.)

Another consequence of the book's narration by Cariad is its tone, which is much lighter (and frankly, argumentative) than the LUNA series. I'd say it shares roughly the same relationship with its other in-universe books that REVENGER does to Alastair Reynolds' REVELATION SPACE series: it's younger in voice, tone, and focus, and it's a touch lower in stakes and tension as a result. The whole novella comes off as a lil scoop of gelato next to the meal that is the LUNA series, and I'm okay with that. I loved the world, voice, and characters of that series with only a couple of exceptions, and THE MENACE FROM FARSIDE let me sink back into that happy place without having to revisit or interrogate ALL of that world's nuanced conversations.

I want more, and isn't that a good place to be?

The Menace from Farside by Ian McDonald 11/12/19 (Tor.com)

Cariad Corcoran is the daughter in a group marriage on the Moon, and she’s definitely the alpha female to a pack of boys, which is just the way she likes it. Her world order is upset when a shift in the marriage brings with it a new sister, one that is much better equipped to turn the boys’ heads than she is. Cariad’s not going to give up without a fight though, and that’s how she winds up trapped on the surface with all her friends facing the worst that the moon can throw at you.

Told in retrospect by Cariad, the author leaves you on the hook until the end. That she’s retelling it all to an AI Therapist should worry you a bit, which is no doubt the author’s intent.

Readers of classic science fiction will recognize the title as an echo of Robert Heinlein’s classic short story, “The Menace from Earth (1959)”, and wonder if McDonald is going to follow up with a similar tale. He does indeed, and though it’s very much its own story, set in McDonald’s rich Lunar storyscape, the setup and a number of touchpoints clearly show this as an exercise in updating the original. If you’ve never read Heinlein’s story, this is a fun read on its own. If you have, it’s fun to see how Ian has worked the old bits in.