These living Dead are raised by Necromancers, or black magicians, who roam the Old Kingdom or live in Death, using Hands to do their bidding. To remedy the problem of dangerous, living dead, there is always a sorcerer with the title of Abhorsen, who is essentially a Necromancer himself (or herself), only in the reverse; he puts the dead to rest. At the time of Sabriel, it is her father, Terciel, who has the job of controlling the endless dead creatures doing evil deeds around the Wall, especially difficult since a new evil seems to be rising.
When the current Abhorsen is overcome by one such evil, he sends his bells and sword to his daughter Sabriel, who is being raised in an Ancelstierre school, out of reach of those who might try to strike at her father through her. She must return to the Old Kingdom to rescue her father and prevent the evil's return.
Sabriel is joined on her journey back to the Old Kingdom by an ancient Free Magic construct of unknown origin named Mogget. Mogget appears in the form of a white cat and is bound by a red Charter magic collar to serve the Abhorsen. Sabriel is told never to release Mogget's collar. Sabriel and Mogget take a craft known as a Paperwing to try to find her father. On the way, they are attacked by the Dead. The craft is wrecked, and in order to save herself, Sabriel releases Mogget. The cat reveals himself to be an incredibly powerful Free Magic elemental. It almost kills Sabriel, but she rebinds him with a ring she received from him a few hours before for just such a purpose.
Sabriel and Mogget then find themselves in the pit of Holehallow, the burial place of ancient royalty, where they come across and free their next companion, the mysterious Touchstone, who has been magically imprisoned as a wooden ship's figurehead for over two hundred years. He claims that he doesn't remember his past, or even his own name. At Mogget's suggestion, he asks to be called Touchstone, even though it is a jester's name, because he secretly remembers his failure to protect his family.
The three of them trek through the Old Kingdom in an attempt to find the Abhorsen. They find him in an underground reservoir in Belisaere, trapped in Death. Since he has stayed too long in Death, he cannot return for long, but with what little time he has left, the Abhorsen tells Sabriel about the evil known as Kerrigor. Kerrigor has risen far from Death and intends to wreak havoc in the Old Kingdom and Ancelstierre. Sabriel releases her father from Death, and once they emerge from Death, father and daughter part for the last time — he, to ring the bell Astarael and delay Kerrigor's havoc; and she, to save Touchstone by bringing him (and herself) as far away from Astarael's music as possible. In the process of ringing Astarael, Sabriel's father releases Mogget.
They succeed, but as long as Kerrigor's body is intact, he will rise from Death again and again. Sabriel and Touchstone use another Paperwing to bring them as close to the Wall as possible, and cross over to Ancelstierre to find Kerrigor's body, following the clairvoyant guidance of the Clayr twins Sanar and Ryelle. They find the body, and Sabriel finally defeats Kerrigor by binding him with Ranna and Mogget's collar.
She dies but the previous Abhorsens prevent her from crossing into Final Death as she cannot die without someone else to take her place as Abhorsen. She wakes up with Touchstone before her, and both Mogget and Kerrigor asleep, bound by Ranna.
Mordicant: One of the Greater Dead. It is created by a necromancer by molding human blood, Free Magic, and a Dead spirit. It can pass from Life to Death at will. It is described as manlike, with eyes like fire, and grey-green flesh that dripped with flames and smoke. Sabriel defeated a weak Mordicant when she was fourteen years old. However, a very strong one pursued Sabriel through the door in the long cliffs and almost across Abhorsen's Bridge. There it led Shadow hands and living human slaves to cross Abhorsen's Bridge until Sabriel called on the Clayr's gift of water, which caused it to flee.
Thralk: A dead spirit that slipped out of Death after the commotion Kerrigor caused in breaking through all the gates single-handedly. It stayed in Life for decades, feeding off humans. It found Sabriel in Life on Cloven Crest while she was in Death, though surrounded by a diamond of protection. Sabriel sensed when the creature broke through her protection, and banished it to death with the Abhorsen's sword and the bell Kibeth. Thralk died when a hunting javelin rebounded off a rock and cut his throat. Touchstone said that his father died in a hunting accident. This makes it possible that Thralk is the re-animated father of Touchstone. However, in Sabriel, it states that Thralk had been struggling in death for three-hundred years, and Touchstone's imprisonment was for two hundred years, so the issue is unresolved.
Shadow Hands: Dead creatures controlled and created by a necromancer. Usually a skilled necromancer uses the heads of dead humans to bring back only their spirits, forming the inconsistent, dark and dangerous substance that is a Shadow Hand. Having no corporeal form, Shadow Hands cannot be stopped by mere force but can be forced back into Death by the bells of a necromancer. Sabriel suspects a necromancer of having formed Shadow Hands from the soldiers close to Cloven Crest. They attack Wyverly College after the Dead Hands are defeated by the soldiers and while Sabriel attempted to destroy Rogirrek (Rogir)/Kerrigor's body.
Dead Hands: Corpses raised by a necromancer to do his bidding. They can be defeated by force, although with difficulty, since the magic in them keeps their limbs and flesh strangely intact. A horde of Dead Hands attack Wyverly College at the end of the book, but are defeated by the soldiers.
Mordaut: One of the weaker Free Magic creatures, a parasite. It cohabits a human body, controlling and hiding in it, and slowly saps the life from it. It comes out at night and takes the life of any other human around it, but returns to its host after feeding. It has no definite form and moves like a pool of darkness. Sabriel encounters a Mordaut on the island of Nestowe, inhabiting the body of a fisherman named Patar. Once she sensed and nearly put it to sleep with Ranna, the Mordaut burst out and killed Patar. However, Touchstone stabbed it with his ensorcelled swords and Sabriel was able to banish it using the bells Saraneth (the Master), Ranna (the Sleepbringer), and Kibeth (the Walker).
Gore Crows: Ordinary crows trapped, killed with a ritual, and infused with a single human spirit by a necromancer. They disintegrate in the sun and wind, and if one makes contact with running water, all its counterparts will be forced back to Death as well. The fewer crows share the human spirit, the stronger they are, but they kill by strength of numbers. They fly seemingly without the use of wings or plumage and are easily suspended by the Free Magic that was used to create them. A horde of gore crows attacks Sabriel when she is flying in the Paperwing after escaping from Abhorsen's house.
Does the Walker choose the Path, or the Path the Walker?
The book departs from the conventional form of fantasy in its resolution not to allude to the stereotypes of the genre. Death is not considered a bad thing as such, and loss is shown to be something that builds character. It also lacks a normal fantasy's sheer cast list, of which there are typically hundreds of incidental characters and many hero-helpers.