Once the potion has been distilled, the alchemist must drink it within 24 hours and focus on a target mortal. The alchemist must make a test using her Intelligence + Science vs. a difficulty of 5. On a success, the ritualist can determine whether the mortal is a ghoul, Touchstone, Contact, or Ally to another vampire. The effects of this formula end after successfully using this potion or if 24 hours have passed without the alchemist making a test to use it.

The alchemist's blood, phlegmatic blood, the eye of a whippoorwill or another nocturnal bird, and a silver thread.