Half a King is a compelling novel by Joe Abercrombie that depicts the treacherous journey of a young prince named Yarvi, who was born with a crippled arm. The story takes place in the harsh lands of the Shattered Sea, where power and brutality reign supreme. Yarvi is the second son of King Uthrik of Gettland, and he has always been treated like an outcast by his father, his brother, and his people.

The novel starts with Yarvi's coming-of-age ceremony, where he is supposed to swear an oath to the Six Sacred Gods and become a man. However, Yarvi fails the test and is deemed unworthy, which causes his father and brother to renounce him and cast him out of the royal family. Insulted and heartbroken, Yarvi decides to seek refuge in a nearby monastery instead of committing suicide, as tradition dictates.

At the monastery, Yarvi discovers that life is not easier, but harder. He is forced to leave behind his royal privileges and live a humble life as a novice, working long hours in the gardens and the kitchens. However, as the weeks pass, Yarvi starts to realize that the monks have their own secrets and agendas, and that they might be as corrupt and ruthless as any other ruler in the Shattered Sea. He also learns the art of deception, as the monks teach him how to read people's faces and tell lies without being caught.

One day, Yarvi receives a message from his mother, announcing that his father and brother have been killed in battle, and that he is now the king of Gettland. Shocked and scared, Yarvi is forced to leave the monastery and embark on a dangerous journey to reclaim his throne and avenge his family. However, he soon realizes that he is not a born warrior, and that he needs allies to survive.

Yarvi meets several characters on his journey, who help or hinder him in different ways. Among them are Sumael, a skilled warrior from the far-off land of Vansterland, who becomes Yarvi's bodyguard; Nothing, a brave and loyal orphan who joins Yarvi's crew; and Jaud, a cunning and seductive queen who offers Yarvi her army in exchange for his hand in marriage.

Yarvi also encounters many obstacles on his journey, such as the harsh weather, the treacherous terrain, and the savage tribes that roam the Shattered Sea. He faces betrayal and ambushes from people he trusted, and he has to fight for his life and his beliefs in many battles. However, Yarvi never gives up, thanks to his wit, his resilience, and his strategic mind.

Yarvi's ultimate goal is to defeat his father's killer, Grom-gil-Gorm, a ruthless warrior who has conquered many lands and enslaved many people. Yarvi knows that he cannot defeat Grom in a direct battle, so he decides to use his cunning and his knowledge of diplomacy to bring him down. Yarvi pretends to surrender to Grom and offers him a chance to become the supreme ruler of the Shattered Sea, but then he uses a secret weapon to poison Grom's army and force him to retreat.

In the end, Yarvi becomes the king of Gettland and marries Jaud, but he realizes that power is not everything. He gives up his dream of becoming a great warrior and chooses to rule his people with compassion and intelligence. He also learns to accept his disabled arm as a source of strength, not weakness, and to value the friendships and the love he has acquired on his journey.

Half a King is an epic tale of courage, betrayal, and redemption, set in a harsh and unforgiving world. It shows how one person can overcome their limitations and rise up to challenges, with the help of others and the power of their own mind. It also raises important questions about the nature of power, the responsibility of leadership, and the human capacity for evil and goodness.