Abhorsen is the third novel in The Abhorsen Trilogy series by author Garth Nix. In this novel, the Abhorsen-In-Waiting, Lirael, and Prince Sameth, who is a Wallmaker, must confront and bind the evil spirit Orannis before it can destroy all life.

It turns out the Ninth Power, which is Orannis, was broken into two pieces and buried inside of two silver hemispheres at the beginning of time. The two hemispheres were then buried deep in the ground. That is until Hedge uses the Dead to dig up the hemispheres in an attempt to reunite the hemispheres and set Orannis the Detsroyer free.

Since Lirael, the Abhorsen-in-Waiting, and their son Prince Samuel believe the Anhorsen Sireal and her husband the king are dead, Lirael and Sam set out to stop Hedge. .Lirael and her cohorts—Sam, The Disreputable Dog and Mogget—are the only ones that have the power to stop the Destroyer from emerging from the hemispheres and destroying everyone.

The group battles the Dead Chlorr, the Dead armies and magical powers in their attempt to save their world. Lirael transitions from the world of Life and Death in her race against time.