The book Incarceron by Catherine Fisher is about a boy named Finn and a girl named Claudia. Finn is inside of a prison called Incarceron that watches his every move and is, actually alive. Claudia, however, lives outside of the prison in the world, and her father is the warden of Incarceron. The story begins with Finn being "flung on his face and chained to the stone slabs of the transitway" (p. 5). He is then "rescued" by a group of people called the Civicry, because of a woman known as Maestra. Maestra examines his wrist to check for injuries from the chains that were around them and finds "the tiny tattoo of the crowned bird," and notices that it's not a Civicry mark and that it looks like the crystal she had found. The Civicry is then attacked by Finn's group (the Comitatus) and Finn takes the Maestra as a "hostage" so that he can find out more about the crystal and his tattoo, since he has no memory of his past until he woke up in the prison. In a trade the Civicry give them the crystal and other gold and jewels in order to get the Maestra back, and Finn gets the crystal, after having a flash of memories come back to him. Finn soon after talks about Gildas about his vision and Gildas finds out about the crystal. Gildas, Finn, and his friend Keiro plan to escape after Finn discovers the crystal is actually a key that could possibly lead them outside. Meanwhile, Claudia is curious about what is in her father's study and, with the help of her teacher, Jared, decides to break in. Once inside she discovers another key that is just like Finn's. Finn and Claudia find out soon after that they can communicate with each other, and Claudia and Finn work together so he can attempt to escape. Claudia decides to help Finn and his friends when she sees the poor conditions of Incarceron and she comes up with the idea that Finn is the lost prince she was supposed to marry, Giles, instead of his brother, Casper.

The style of Catherine Fisher is very detailed and descriptive, which allows you to picture what is going on in your head, like when she wrote "Claudia wore a dress of red silk with a lace bodice and sat opposite Lord Evian, while her father at the head of the table ate sparingly and spoke quietly, his calm gaze moving over the nervous guests." (p. 42-43). The author has a voice that is very different and unique from other books because it tells about a place that sounds like it's earth and it's set in the future, but it's a future where things are set back to older times when there were kings and queens that ruled and they have to use less modern medicine because they aren't allowed to use newer technology. The author's voice is also different because she also describes advanced technology that was used to create the now living prison that watches over everyone inside and can communicate with them if it wishes. I like how the author wrote the book so that almost every other chapter it rotated from Finn to Claudia.

The two main characters in the book are Finn and Claudia and the writer does make you believe in them as people because they aren't invincible and have faults and problems just like everyone else, like when Finn gets a vision. They also get into fights like when Claudia fought with her father and when Finn fought with a girl named Attia about whether or not his "brother" Keiro was trustworthy or not. I liked both Claudia and Finn because they both seemed honest and believable, like they could be real people, and because the author gave them each goals and a mindset that gave you a better idea of who they were, and with Finn and his memory flashes, who he was or could have been. I like how determined Claudia is in the story, like when she said "II thought we'd have time, but a few days! We have to act, Jared. I have to get into the study, even if your machine is untested." (p. 49).

The settings of the book are inside of Incarceron, and outside of Incarceron, at Claudia's home, and then the palace where the queen lives. The outside world, where Claudia lives, seems a lot like earth to me, just earth set in older times with modern technologies. The people in the book live in a world where, even though there is modern technology, they are not allowed to use it because they do not want to mess up the simplicity of the time.