The Revelation spell seems to help witches track the sources of magic (other than their own) which they happen to take an interest in, even if the target is hidden or altered by magic, which is able to fool normal human sighting.
The spell needed an alignment of candle and special necklace. A phrase then recited multiple times.
- Reveal Now, Reveal Now, Reveal Now
After the recitation, the necklace will glow purple and point in the direction of the target.
Alternatively, the spell can be cast by simply pointing at the target and reciting:
- Reveal Now, Reveal!
After using it on Tasha Banes' clone, the latter revealed to Max Banes the location of the source of the magic controlling it.