Dragonlance Chronicles starts at the end of the 5-year personal quests of the book's heroes. The Preludes series provides some specific stories from the 5 years leading up to Chronicles, and Flint the King, the fifth book, is about the dwarf Flint Fireforge. Interestingly, we already know what happened to Flint in the years leading up to Chronicles, because he reveals it to Tanis shortly after the Heroes of the Lance join forces, however reluctantly, with the Aghar (Gully Dwarves). Flint says that he spent most of the five years as a captive of Gully Dwarves, which is why he despises them in Chronicles. This book provides a slightly different version of that story.
This book actually begins as a murder mystery. Flint, a hill dwarf, returns to Hillhome, his childhood hometown, only to discover that his brother Aylmar died about a month ago. As is usually the case with small villages, rumours are unavoidable and eventually Flint hears that some folks believe that his brother was murdered by Theiwar dwarves (those are the Derro of Krynn). The murder mystery begins, but just as quickly another surfaces: What are Theiwar dwarves doing in Hillhome?
As we know from the Legends trilogy, the Theiwar dwarves locked themselves in their mountain homes when the Cataclysm struck Krynn. It's been called The Great Betrayal ever since, and the hill dwarves don't consider the mountain dwarves kin, and in fact view them mostly as enemies. But lately, the Theiwar have been on the move for some reason, passing through towns like Hillhome on their way to and from Thorbardin. Nobody knows why, and most business owners in Hillhome view it as a convenient way to overcharge the Theiwar, eager to liberate them of coin as payback for their cowardice 100 years before.
Flint's investigation of course leads him into the den of the devious Derro dwarves, where he meets Pitrick, the hunchback mage and advisor to the thane. Pitrick seeks to destroy the hill dwarves in a crusade meant to prepare the way for (of course) the Dark Queen herself.
While in the Theiwar mountain city, Flint meets Perian Cyprium, the captain of the guard and the disinterested love interest of the evil mage Pitrick. When Pitrick starts torturing Flint within inches of his life, Perian steps forward to defend him. Flint and Perian both end up in a deep monster pit, presumed dead by Pitrick and his guards.
Of course they're not dead, and they do battle with the monster before being found by a clan of Gully Dwarves living in a cave system around the pit. The Gully Dwarves, being Gully Dwarves, decide that Flint and Perian are their new king and queen.
Flint barely endures this at first, but eventually he and Perian become friends and even learn to enjoy living with the Aghar. There's no way three years pass during this time, and I'm pretty sure Flint had said he was captive for three years, but regardless of any confusion, the shift of the context of Flint's "captivity" is a lot of fun. Only Flint would describe being crowned king as captivity.
Eventually, Pitrick discovers that Flint and Perian aren't actually dead. He launches a fullscale attack on Hillhome, partly because that's been his plan all along and partly to draw his new personal enemies, Flint and Perian, out of seclusion. A skirmish erupts between the Derro against the dwarves of Hillhome and their unlikely Aghar allies. Before the battles begin, Flint and Perian realise their true feelings for one another.
In the end, Flint and the Aghar are victorious, although Perian sadly perishes.
I admire how these prequel books work Takhisis into the story in really understated ways, but I have to admit that almost every single Prelude story has some encounter that doesn't feel quite right. In Darkness and Light, it feels strange that Sturm and Kitiara meet a good dragon when in Chronicles it seems that everyone believes good dragons are a thing of the past. In Riverwind the Plainsman it feels particularly odd that the same black dragon that kills Riverwind in Chronicles has already encountered and hunted and battled him before. And in this one, it feels wrong that Flint has encountered Draconians.
As a counterpoint, RA Salvatore wrote prequels to the Crystal Shard and they feel entirely as if he'd written them in order. The prequels set up questions and problems that are resolved in later books, and they never answer something that's still a question later on. I wish Preludes had been similarly structured.
Overall, though, this is another good Preludes book. As with many of the other ones, it doesn't fit perfectly into the continuum of lore but they're good stories that ring true enough to be mostly believable. Just like in real life, sometimes stories get exaggerated in the re-telling, and who's to say that's not the case with Preludes? So what if Flint was king for a few months and not a captive for 3 years. It's worth it, and I don't know any Dungeon Master who wouldn't allow it under the Rule of Cool.