Michelle West, reviewer
At over 600 pages, this is a brick of a book. It is also, at over 600 pages, very easy to read; you never feel its length, and in fact, if Emerson had chosen to go on for another couple of hundred pages, I wouldn’t have minded at all.

Adrian Mercati is thrown into the role of Protector of the City of Diamond, one of the Three Cities vast interstellar spaceships with whole religious cultures based on a murky past and an alien intervention. Not that he doesn’t want the job, and not that he’s not the man for it, but at twenty, he’s a tad on the young side. He immediately makes arrangements for a political marriage to Iolanthe of the City of Opal, a seventeen-year-old who makes him seem worldly and wise. This marriage is viewed in a much better light than other choices he’s made in particular, his choice of a personal guard. Tal Diamond is an Aphean, a human-Elephite cross-breed. Commonly called demons on the Cities, and illegal everywhere but the Empire, Apheans are apparently always sociopaths, and none has ever survived to the age of forty, with most dying a lot earlier than that. Tal in turn has chosen two unlikely servants: Spider, a man who lives on the fringes of legality (well, okay, off the fringes, but he’s an unaccountably likable character, so I want to be nice) and Keylinn Gray, one of the legendary Graykey a group of people who are apparently dedicated to the service of others, and who will do everything, including die, to live up to their contract.

Add to this mix the hunt for a legendary artifact (the Sawyer Crown, named after Adrian Sawyer, who is considered the founding father of the Three Cities), and a rather bitter rivalry with the City of Opal, and you’ve got City of Diamond.

This is a terrific winter book, and would also probably be a terrific beach book. It’s complex enough to hold the interest, and accessible enough to read after a long hard day. The characters are people you’d like as friends, and there’s something about the whole novel that feels like the good parts of Jane Austen, although I couldn’t say why.

Only complaint: It’s the first of more than one. And it’s only a complaint because I want number two now.

Locus Carolyn Cushman, reviewer

Fans of both sociological SF and space opera should check out this excellent novel set on a pair of massive city-ships in space, built by aliens but inhabited by human Redemptionists, religious fanatics who promised to spread the aliens’ message. With time, however, their interpretation of that message changed, and the ships Diamond and Opal went to war over issues of theology.

A new Protector on Diamond seeks to mend the breach through marriage with a lady of Opal, whose entourage includes spies and scheming priests. Intrigue and culture clashes naturally ensue, particularly since the Protector enjoys shocking people, and employs a sociopathic, half-alien “demon” as his right-hand man. Characters from the lower classes (both cops and robbers) and from outside the Cities (the half-alien and a contract assassin) add some unusual, even unpredictable outlooks, the exploration of which gives the novel its most serious, and intriguing side.

The cast is large, but the characters are an entertaining and memorable bunch, and their lives serve to show the fascinating shipboard cultures. The plot quickly gets away from court and royal wedding (romance is at most a minor issue) and devolves into two parallel quests: the two cities race to find a religious artifact, while the half-alien searches for others of his own kind. Both quests are successful, but ultimately raise more questions than they answer. The ending works very well in its own way but I hope there’s more to come.