Thaumaturgy is the process of creating magical links between objects or people. Magic flows through one object and is attached to the other.
Harry Dresden says: "As above, so below. Make something happen on a small scale and feed it enough energy to happen on a large scale." Most thaumaturgy requires something to connect the object being used to the greater object, such as blood, hair or nail clippings, etc. 
Thaumaturgy is employed in various ways. The most well-known example is the voodoo doll, which is a doll magically connected to a person.
- 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.
- TO BLOCK 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:
- If using blood from a relative, there maybe something more than simple blood relation involved, maybe there needs to a bond, a sense of family
- Maybe there's some kind of magic that jams or conceals
- Maybe it's distance. Some wizards have tracked as far as a couple of thousand miles but that's not so common or easy.
- There is no blood, hair, or nail clipping available
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
- ↑ 1.0 1.1 1.2 Storm Front, ch. 2
- ↑ Fool Moon, ch. 19
- ↑ 3.0 3.1 White Night, ch. 14
- ↑ 4.0 4.1 4.2 Turn Coat, ch. 30
- ↑ Changes, ch. 24
- ↑ Storm Front, ch. 16
- ↑ Proven Guilty, ch. 6
- ↑ Proven Guilty, ch. 33
- ↑ Proven Guilty, ch. 34
- ↑ Ghost Story, ch. 21
- ↑ Cold Days, ch. 27
See also Edit
- Circle of Power
- Little Chicago
- Harry Dresden's spells
- Grey Cloak
- Molly Carpenter