Katsa lives in a world where people with different colored left and right eyes are people who have unnaturally enhanced skills and talents compared to ordinary folk. Such people are called Gracelings and are feared and avoided by regular folk and put into mandatory servitude by monarchs. Katsa is a noblewoman graced with the power to kill and often sent on dangerous missions by her tyrant of a uncle, King Randa of the Middluns. To make up for all the dirty deeds she's been forced to perform on innocents, Katsa leads a council of justice-fighters who work secretly against tyrants like King Randa. Katsa is not proud of her skill - she lives with the guilt of having accidentally killed her cousin and this guilt forms part of her psyche every time she has to use her powers.
The story opens with her on one of her council missions to free the King of Lienid, King Tealiff from another King's dungeon. During the mission, she encounters Po, another Graceling whose powers and motives Katsa can't quite figure out. After returning from the mission, Po appears at the Middluns court. Katsa is both annoyed and intrigued by him because unlike other strangers who usually shirk away from her in fear when they find out who she is, Po is very comfortable in her presence. Po observes her training and joins in. She finds Po a challenge when it comes to fighting, he seems to be able to guess her every move and prepare counter-moves - all of this is very refreshing for Katsa who is used to winning fights easily.
Soon, Po reveals that he has searched for the Council in order to find information about the whereabouts of his grandfather who happens to be the King Tealiff. Po and his grandfather are reunited and Po joins the Council. The council find out that King Tealiff was kidnapped and put in another King's dungeon. Everyone is puzzled as to the motives. Po decides to stay in the Middluns court until his grandfather heals. During his stay, he and Katsa get to know each other and Katsa finds him a truly kind-hearted man. What is confusing is how much this is at odds with his unnaturally good fighting skills.
One day, Katsa figures out why Po is so good at fighting her. It isn't because he has good fighting skills, it's because he can read her mind and see her plan her next move. She feels betrayed by Po at first, but after he explains himself she finds that she can relate to his situation. Like her, his powers are looked upon others with fear because they can be so easily abused. Eventually, Po reveals that he thinks the culprit behind the kidnapping is King Leck of Monsea. Po also eventually convinces Katsa to refuse to be a servant for King Randa and Katsa puts herself in a dangerous position by disobeying her Uncle. Katsa and Po leave her Uncle's court and journey towards Monsea. During the journey, Katsa falls in love with Po, despite her own qualms about getting into a relationship. She also learns that her so-called Grace might actually be Survival not Killing.
As the two approach Leck City, Po becomes more and more anxious. They figure out that Leck might be torturing/abusing his own daughter and other young girls, Bitterblue and that is the reason why the Queen and her daughter have hidden themselves away. Po has suspicions that King Leck might be Graced with some sort of power that allows him to control others. He makes Katsa promise him that once they enter the city she'll do what he says no matter what and Katsa, though puzzled, agrees. Soon after, Katsa finds herself compelled to kill a woman who was running through the forest. Po prevents Katsa from acting, however, the woman is shoot down by her husband, who turns out to be King Leck. Po commands Katsa to shoot King Leck, but Katsa won't and they lose their chance to act. Katsa realizes the extent of King Leck's power to influence her thoughts. Eventually, Po, using his powers to sense thoughts, finds King Leck's daughter, Bitterblue. Po must enter King Leck's castle to kill the King because he's the only one who can resist the King's power. Katsa must remain behind to guard Bitterblue.
Katsa waits for Po to return from his mission. When he does return, he's barely alive. And he has failed the mission. Now, King Leck will be coming after them. After a tearful discussion, Po decides that he is too injured and he will hamper their escape so he tells Katsa to go ahead with Bitterblue while he hides from King Leck. Katsa takes Bitterblue out of Monsea and towards Lienid for safety. Though Katsa is good at surviving, the two of them have to cross Grella's Mountain Pass which is under snow. Bitterblue barely survives the trip through the pass.
Eventually, Katsa and Bitterblue will arrive at the Lienid Court where they will have to confront King Leck. Katsa will have to rely on her immense courage and love for Po to resist the King's influence and kill him.
Best part of story, including ending:
I enjoyed the creative description of the Graceling powers and the interesting twist on Katsa' killing graceling as a survival graceling.
Best scene in story:
My favourite scene is when Katsa looks into Po's eyes for the first time and he sends her a smirk which she interprets as cocky. I like that scene because it sets up an interesting dynamic between the two soon-to-be lovers.
Opinion about the main character:
I like that Katsa and Po had an unconventional relationship for their time.