This is a book that centers around one city and three main characters. To quote book blurbs:

- Elantris was beautiful, once. It was called the city of the gods: a place of power, radiance, and magic.
- Raoden, prince of Arelon, was loved by all, including the princess he'd never met.
- Hrathen, high priest of Fjordell, will convert the people of Arelon or kill them.
- Sarene, the princess of Teod, was a widow before she was ever married.

Back in the "good times", citizens of Arelon would wake to find themselves "converted" to Elantrians, near-immortal beings able to wield indescribably powerful magic. They would abandon their old lives and move to the city of Elantris to lead their new god-like lives there. But when the book starts, Elantris has fallen. Nobody knows how or why, but something went wrong and the once-beautiful city is now dull and ugly and covered in filth. Those who were once Elantrians are still undying but no longer in a good way; patchy-skinned, hairless, hideous creatures who cannot heal and therefore eventually go insane from an accumulation of their injuries over the years. Worse of all, Arelon citizens still "convert", but now that conversion condemns them to the same hideous undeath.

When Raoden, prince and heir of Arelon, awakes to find himself cursed by the Elantris transformation, his father covers this up by claiming the prince has died outright, while shipping Raoden off to Elantris and holding a closed casket funeral. Sarene, his betrothed, arrives just in time for the funeral, never having met her fiance in person, and discovered that due to the terms of the marriage treaty she is now considered to legally be his widow, and banned from remarrying or returning home as that would void the terms of the treaty. Stuck in Arelon and somewhat suspicious that the prince's death was suspicious, she starts investigating the court, and when she uncovers a plot by Hrathen and the priests of Fjordell to convert and annex Arelon, she throws all her frustrated energy into finding a way to undermine this.

Hrathen, meanwhile, is dealing with his own internal struggles and political problems within the priests he's supposed to be leading, as well as the defiance of Sharene and his genuine belief that he must convert Arelon in order to save their lives.

Raoden, cast into the slime-coated city of fallen Elantris, tries to understand what's happened to him, and then to Elantris as a whole, spending most of the book trying to puzzle out what the cause of the curse is and ways to help the poor Elantrians. For most of the book Raoden and Sarene are working toward similar goals but unaware that each other exist - Sarene because she believes Raoden is dead, and Raoden because he assumes Sarene would never have come, or would have gone home, on learning of his death.

Overall a very enjoyable book with a complex world system, interesting characters, and lots of plot twists. However, as with the Mistborn trilogy I do think characters are Sanderson's weakest point. Raoden seems to be a beloved golden child who can persuade almost anyone to do what he wants with "natural leadership" to a fairly ridiculous extent. Sarene appears to be perfect at practically everything but drawing, and for some reason spends half the book annoyingly and unbelievably complaining that she's never going to have a real wedding and no man would ever like her. Hrathen is more interesting in general but at the end does an abrupt change of mind that completely changes the plot and feels rather heavy-handed and unexplained. Overall the book was still very enjoyable, but in a few places you'll just want to grit your teeth and try to overlook the character flaws.