The Last Argument of Kings, by Joe Abercrombie, is the third and final book in The First Law trilogy. It takes place in a grim and brutal fantasy world, where the Union, the Northmen, and the Gurkish Empire are at war. The novel follows the struggles of several characters, each with their own personal agenda, as they navigate through the political and military conflicts that threaten to plunge the entire realm into chaos.

The novel opens with the Union army on the brink of defeat. After the crushing defeat at the battle of Carleon, King Jezal dan Luthar and his troops have been pushed back to Adua, the capital city. But with the help of the mysterious, and deadly, Bayaz, the Master of the Magi, they manage to turn the tide of the war. Bayaz has been working in the background, manipulating events to ensure the Union's victory, but he has his own hidden agenda.

Meanwhile, the Northmen, led by the infamous warrior, Logen Ninefingers, are making their way to Adua. Logen hopes to find peace in the city, but his violent past has a way of catching up with him. As the Union army celebrates their victory, they are unaware of the threat looming on the horizon.

In the midst of all this, the former torturer, Sand dan Glokta, is caught up in a web of political intrigue. He is tasked with protecting the Union from the Gurkish Empire, but he soon discovers that his new superiors are just as manipulative and corrupt as his old ones. When he sets out to investigate a dangerous conspiracy, he finds himself in a deadly game of cat-and-mouse with mysterious and powerful enemies.

As the tension rises, each character's role in the final conflict becomes increasingly clear. Bayaz reveals his true intentions, and Logen is forced to confront the darker aspects of his past. Jezal must navigate the politics of the Union and make the ultimate sacrifice to ensure its survival. Against a backdrop of war and betrayal, Abercrombie delivers a powerful and poignant conclusion to his dark and gritty trilogy.

In the end, The Last Argument of Kings is a triumph of storytelling. Abercrombie has created a vivid and brutal world, with meticulously crafted characters and a sweeping plot that keeps readers on the edge of their seats. The novel explores themes of power, morality, and the consequences of human ambition, through the perspectives of its diverse cast of characters. It is a fitting end to The First Law trilogy, and a testament to Abercrombie's skill as a writer.