In the future, a near feudal colony has risen up around the industrialisation of the Moon, and though technology keeps the deadly natural environment at bay, the four basic essentials of life—air, water, carbon and data—come at a price.

The Moon is controlled by five families, dubbed the Five Dragons: the Australian Mackenzies dominate mineral extraction, the Asamoahs of Ghana control a vast underground agricultural industry, the Russian Vorontsovs run the transportation systems, the Suns of China are masters of technology, and the upstart Brazilian Cortas mine helium-3 to power Earth's fusion reactors.

Lucasinho escapes the locked-down Corta palace, and his finances are cut off by his controlling father, Rafa's harsh and calculating younger brother Lucas.

Jonathan Kayode, the leader of the LDC called the "Eagle of the Moon", forces the Cortas to agree to marry Lucasinho to Rachel's half-brother Denny Mackenzie by threatening their rights to the new claim.

Lucas is trapped in a rover on the Moon's surface after it is hacked by his ex-wife Amanda, who reveals that she and her family have been behind the assassination attempts as part of their plan to manipulate the Cortas and Mackenzies into destroying each other.

"[6] He wrote, "When I began writing Luna, I knew I would be building a world from scratch, but also one that adhered to the constraints of the physical realities of the Moon ...

"[7] To this end, he instituted what he calls "a ticking clock", explaining that "if you’re on the Moon for more than two years, your bone structure and musculature will degenerate to the point to where it’s not safe to go back to Earth again, so everyone who goes there to work has to decide, 'Do I stay or do I go?

[7]Science fiction editor and critic Gary K. Wolfe noted in Locus, "[McDonald's] moon colony is resolutely multicultural ...

[9] Wanting to illustrate the various aspects of life on the Moon—industry, economy, social interactions and day-to-day conditions—McDonald noted the importance of the character Marina Calzaghe, a newcomer to the Moon.

[9] He said: The rookie is a fantastic tool for worldbuilding without info-dumping ... [Marina] ends showing us the inner workings of lunar industry, society, law, sex, marriage and the Corta family.

[5] McDonald previously published the prequel novelette "The Fifth Dragon", featuring a young Adriana Corta, in the 2014 anthology Reach for Infinity.

[2][3][4] Cory Doctorow wrote for Boing Boing: Ian McDonald's never written a bad novel, but this is a great Ian McDonald novel ... [it has] the fashion sense of William Gibson, the design sense of Bruce Sterling, the eye for family drama of Connie Willis, the poesie of Bradbury, and the dirty sex of Kathe Koja and Samuel Delany.

"[4] Publishers Weekly praised the novel, saying "McDonald creates a complex and fascinating civilization featuring believable technology, and the characters are fully developed, with individually gripping stories.

"[14] Writing for Locus, Gary K. Wolfe called Luna "the best moon novel I've seen in many years", noting that "the most relentless, merciless, unforgiving character of all is the lunar setting, which McDonald manages to present as utterly boring and absolutely terrifying at the same time.

"[8] Though describing the novel's first third as "tremendously dense" and potentially inaccessible to readers, Niall Alexander of Tor.com called the book "almost monolithic in its ambition" and praises its "unadulterated greatness",[2] writing: In its gravitas and tension and, alas, tragedy, it’s damn near Shakespearian.

[2]Carrie Mok of SciFiNow wrote, "McDonald certainly shows off the well-developed Cortas to illustrate his knack for creating dynamic human relationships that encompass the whole Moon ...

"[15] Comparing the novel's dynastic struggles to those of Game of Thrones and Frank Herbert's Dune, SFF World's Mark Yon called the last quarter of the book "a tour de force of heart-stopping, page turning moments".

[16] Tom Shippey of The Wall Street Journal wrote, "It’s a great scenario, lovingly detailed, and curiously attractive despite its current of unforgiving violence.