Ectomancy

Ectomancy is a form of magic. Ectomancers are sorcerers who are able to call upon ghosts of the dead, to provide closure to a grieving family or gather information.

Description
A good Ectomancer has a sensitivity to spiritual energies and apparitions—ghosts.

Grave Peril
In Grave Peril, a well known ectomancer, Mortimer Lindquist, is leaving town. Morty is scared of some super ghost that is coming. He has a theory that the barrier between this world and the Nevernever is slowly being torn away. He says that the border has been waggling back and forth for the last two weeks. The instability has been making it easier to form bigger, stronger ghosts when people die. Soon, the border will be so thin that there will be more problems with demon attacks than Gang violence.

Dead Beat
In Dead Beat, Harry visits Mortimer Lindquist to learn what he knows about the threat of the necromancers in town. While there, he tells Morty that he thinks he is one of the most powerful ectomancers that he knows and that Morty could do a lot of good in the fight against the Red Court vampires having access to all kinds of informations via ghosts and spirits.

Ghost Story
In Ghost Story, Harry's ghost goes to Morty to enlist his help to communicate to the people who can help him solve his own murder. While there, a gunman comes to abduct Mortimer for the Grey Ghost. Morty calls several ghosts to him including Sir Stuart Winchester, and with their aid, Morty defeats the gunman. Later, the Grey Ghost—Corpsetaker—does kidnap Morty for the purposes of taking over his body for the use of his magic. Because Corpsetaker needs Morty's permission, she tortures him believing he'll relent eventually.

External references

 * Ectomancy and what the hell it is | Locke's Amazing Ghostly Wonderblog