Thaumaturgy is a kind of magic that operates on its target indirectly. Thaumaturgical spells create links between a symbolic representation of the target and the target itself.
Harry Dresden described thaumaturgy to Karrin Murphy this way: "As above, so below. Make something happen on a small scale and feed it enough energy to happen on a large scale." Thaumaturgical spells can be cast from a greater distance than evocation spells, and the practitioner doesn't need to see the object to be affected, either.
Thaumaturgical spells operate by creating magical links to their subjects. In order to establish such a link, a practitioner of thaumaturgy needs to posses something with a connection to the object to be affected. A fragment of an object remains magically connected to the whole it was once part of, so the simplest way to get a magical connection to something is often to take a piece of it. A being's true name also has a magical connection to it.
- Tracking spells: are like any kind of targeted thaumaturgy: create a link, channel to target, pour energy into that channel. With a tracking spell, you are setting up a continuous trickle of energy and then following it to the target.
- Blocking a tracking spell: is to prevent that channel from ever being formed. The way to do that is to shield the target from whatever focus you are using to create the link. — Like if the focus is hair, then you'd shave the head of the target. Also, a good Circle of Power would do the job with enough time and money to give it juice. Theoretically, you could also go into the Nevernever.
- Possible failures:
- a bond, or a sense of family may be needed in addition to the blood of a relative;
- a concealing spell or a jamming phenomenon;
- the distance involved.
In the series Edit
- Main article: Storm Front
Harry uses a tracking spell to find the hair that Gimpy stole off his head, it leads him to Marcone at the Varsity. Harry uses a few strands of his hair plus the blood and skin from their fight in a circle, then says sergui votro testatum.
- Main article: Proven Guilty
In Proven Guilty, Dresden built a thaumaturgical model of Chicago, named Little Chicago. Later, he uses it to track where the Fetches took Molly Carpenter through into the Nevernever. The first attempt didn't work because Molly's baby hair was too old. The second try they used Charity's blood and it worked.
- Main article: White Night
- Main article: Ghost Story
- Main article: Cold Days
In Cold Days, Harry was attacked, beaten and nailed by Ace, Captain Hook and Redcap. Harry Dresden, Waldo Butters, and Thomas Raith are worried about what his enemies could do with his blood that was left behind.
In the TV seriesEdit
In the show of the same name, thaumaturgy is synonymous with black magic.