When Sabriel was a newborn baby, she almost died. Luckily for her, her father is the Abhorsen, the most recent (besides Sabriel) in an ancient line of people who lay the Dead to rest--the opposite of a necromancer, in other words. Whereas necromancers raise the Dead and use them for their own purposes, Abhorsens find Dead spirits that have made their way into the world and send them deep into death, so that they will not find their way out again, and can instead rest peacefully. With his daughter dying, Abhorsen plunges into Death to save her. He is able to pull her back to Life before it is too late, but he makes an unpleasant discovery at the same time--a Dead spirit called Kerrigor is beginning to fight its way out to the living world...
Eighteen years pass, and Sabriel is now enrolled at Wyverly College, where she has been educated since she was five years old. Aside from her regular classes, she also learns magic--Charter Magic, the "good" type (as opposed to Free Magic, the dangerous and dark magic of necromancers and the Old Kingdom, on the other side of the Wall--Wyverly College is located in Ancelstierre, south of the Wall). But there are some things that Magistrix Greenwood can't teach her, and so she learns the trade of the Abhorsens from her father, who visits a little more often than the headmistress of Wyverly thinks. She memorizes the Book of the Dead, learns how to use the seven bells that can control the dead, and even does a little fighting of the Dead herself. But one night, a Dead spirit shows up in one of the school's dormitories, and Sabriel is called to deal with it. It proves to be no ordinary haunt--it's a messenger from her father, and he has sent her his sword engraved with Charter marks and the belt with the pouches for the bells. She knows what this means--either Abhorsen is dead or trapped in death, and she must save him. A journey into the Old Kingdom follows, but it is clear that much more is horribly wrong than just Abhorsen being trapped in death. Sabriel ends up with a sarcastic cat spirit named Mogget and a confused young man named Touchstone at her side, and the three of them work to save not only Abhorsen but all of the Old Kingdom and Ancelstierre, too.