This book is about Elena, Damon, Meredith, and Bonnie entering "The Dark Dimension" to find the 2 pieces of a key to rescue Stefan from a prison called the Shi No Shi. He ended up there because of a deal he made with Shinchi (one of the fox demons).
It starts with a summary of the last book, which I really appreciated as a lot happened in the last book. The last book ended with Elena, Damon and Matt going to find the Dark Dimension. Matt and Damon disagree a lot though so they take separate cars half way to Arizona (where the gate to the Dark Dimension is). Elena and Damon take one car and Matt takes another. They say they will meet up closer to their destination but before they split up, they get into an argument. Matt returns to Fells Church unknowingly to Elena and Damon at first. I honestly thought it was pretty pointless having Matt along in the first place if the author is just going to send him back. Why not just have Elena and Damon go?
In a motel room Elena has a moment of discovery, when Damon lets her in, beyond his boundaries. There she makes a discovery that Damon has kept hidden for centuries. It's inly because of the bond that they share that she can see it.
Bonnie and Meredith turn up wanting to go on this quest to the Dark Dimension with Elena and Damon. Elena wants to protect her friends but finally relents and let's them come along. Before they all reach the Dark Dimension, Damon informs the girls that they will be seen as slaves as that's the only way to get there. Elena isn't sure about this but again she relents as this is the only way to save her beloved Stefan.
In the Dark Dimension the girls have to be tied up to prove that they are slaves to Damon. Elena sees a slave (Ulma) getting whipped and abused by her master (not Damon). Of course Elena stops the abuse and gets herself in trouble at the same time as that is the way things work in the Dark Dimension - slaves get punished for doing things wrong. The woman she saves is in fact pregnant and an heiress who was stolen from her family, the rest of whom were killed.
The story hit a few slow points after that such as Elena getting punished for stopping the abuse of the slave (remember the Dark Dimension has different rules to the real world), the slave and Elena getting treated by a doctor. Elena was treated partly by Damon. A vampire kiss can heal any wound. Damon also released Elena, Meredith, Bonnie and Ulma from their fake slave roles. Ulma is then referred to as Lady Ulma because Damon gives her the property that he acquired when he killed her previous master.
In the last book one of the kitsume (the horrible fox spirits who ravaged the people of Fells Church in the previous book) Misao gave Elena clues about where she could find the fox keys needed to rescue Stefan. She said that one of them was at a ball...so that's where the characters go. At this ball Elena and Damon manage to find a key.
After the ball, Elena is informed that she can in fact go and visit Stefan if she so wishes. Of course she does, but she makes sure that the men who travel with her are dressed in rags because she doesn't want Stefan feeling out of place among them but she dresses lavishly, which I didn't really understand.
When they see Stefan he is in bad shape. He doesn't at first realise it's them I don't think. Damon can't handle seeing Stefan that way so he leaves. Stefan is being kept in a cell that's made of sharp wires. Elena tries to feed him blood to strengthen him a little. When that's almost impossible to do (because of the type of cell he's been put in), she sees that in the next cell the prisoner has some Black Magic wine (the other drink that vampires can tolerate). She asks if it's okay if Stefan has some of this. The answer is yes so Elena works out how to feed him some Black Magic Wine. This makes him quite a bit stronger. When the guards come to take Elena away she obviously doesn't want to leave Stefan.
When Elena sees Damon again, she asks him why didn't he stay to talk to his brother. Damon admits he feels guilty about how Stefan got there. Elena tries to console Damon because it wasn't his fault. He was manipulated by the fox demons.
A few days after seeing Stefan, Elena, Bonnie and Meredith get ready for the 2nd ball (where the other half of the key to free Stefan is hidden). The girls notice that there is a lot of jewellery to go with their dresses so they ask Lady Ulma why? Ulma states that the girls and Damon might not return after this party (as they'll have all the need to save Stefan) so Ulma and her partner (a slave that Damon bought) give the girls the jewellery for bargains or payment when they try to make their escapes with Stefan.
At the 2nd ball, Elena has to be whipped by Damon again because the people want to see that it wasn't a trick before - that she didn't suffer. The 2nd half of the fox key is in the nest of an evil bird like creature. When they get find the key they run to the Shi no Shi and manage to free Stefan. The evil bird creature is chasing and trying to kill Elena and her friends for trespassing to her nest.
They return home to find Matt and Mrs Flowers still at the boarding house. Then a illusion of Shinichi (the fox demon that started all this mess) appears. He says that Elena and friends have worse to come yet. They try to kill Misao (Shinchi's sister) but fail. The next day Damon touches a bouquet of flowers that was meant for Stefan - and something unexpected happens...
I thought this book was okay but I felt that there were bits that didn't need to be in the story (my review only highlights the important things). That's why I only give it 3 stars. It had funny moments as well though :).