Aisha Nasir is the thirteen-year-old daughter of archaeologists who've been working on the almost-abandoned planet of Nevermore for most of her life.
When Aisha, in an excess of enthusiasm, tries to blast open a hidden chamber in the mountain near their settlement, things go predictably wrong and she finds nothing useful--but a strange man turns up, apparently from nowhere.
He looks and sounds like the natives--but not exactly. He seems not to remember his name, and Vikram, one of senior staff of the expedition, dubs him Rama. He proves good with the horses, and Vikram hires him.
When their parents and others go off for annual offworld vacation, Aisha and her brother Jamal are left behind as the consequence for their unauthorized use of explosives, with Vikram and their Aunt Khalida to supervise.
There's a complex background here, that's not easy to summarize quickly without spoilers. Khalida is a Military Intelligence officer on leave after an assignment that ended traumatically. She's been "healed" mentally, except that it was a slapdash job, and another reason for her to distrust the already distrusted Psycorps. Meanwhile, with her official thirteenth birthday approaching, Aisha is awaiting her evaluation by Psycorps--which could result in her being involuntarily recruited into Psycorps, instead of being able to follow her parents into archaeology.
But neither Khalida, nor Aisha, nor even Psycorps knows what's really in wait for them. Rama is not just a wandering nomad. He's the Sleeper, an admired, worshiped, and finally dreaded king and emperor put in stasis and buried in a sealed fortress six thousand years ago. He's been sleeping ever since, and Aisha awakened him, unintentionally and for reasons that don't become clear till later. He's awake, he's a psi master beyond the imagination of Psycorps, and he has a mission foreseen dimly by the precogs of his time. It's time to face the danger his people fled, a thousand years after he was condemned to sleep until awakened.
Rama, Aisha, and Khalida are going to cross the galaxy and the barriers of space-time in an adventure in which the Psycorps Khalida hates and Aisha dreads is a minor obstacle on the path to the real enemy, and the secret of where Rama's people disappeared to. We have living ships, Psycorps agents as malevolent as Khalida thinks they are and Psycorp agents who really do mean well, and people on the edge of United Planets space who have their own agenda.
And there are the Gates, and the secret of where Rama's people went, and why.
It's a great adventure that I'm describing poorly.
In addition to the great adventure, this book has some interesting features. There's reason to think that the core of the story may have been written in the 1970s, when Tarr was trying to sell space opera and the publishers wanted fantasy from her. One of the things that becomes clear some ways into Forgotten Suns is that Tarr's 1980s Avaryon books are the pre-history of this story, tweaked to look like fantasy. This perhaps explains why I got a "seventies" vibe from the book, even while the basic social assumptions, including gender equality and same-sex relationships being taken for granted as just "how things are," are very much the social assumptions of the 21st century. And that's a bonus extra for me: the story-telling I loved about the seventies, without the sexism that frustrated me and the homophobia I was still learning to notice.