The mage can hide himself from other willworkers’ magical senses when he attempts to scrutinize or dispel their magic.
Normally, mages cannot sense if their spells are being tampered with, but the Sense the Threads ability, allows a mage to monitor the status of his spells. With Unseen Spy, a mage can attempt to hide from such a mage’s magical senses.
Whenever a spy scrutinizes a vigilant caster’s spells or tries to dispel them, a reflexive Intelligence + Subterfuge roll is made for the spy, contested by the subject’s reflexive Wits + Occult roll. If the Unseen Spy exceeds the caster’s successes, his spying goes undetected.
Free Council Rote: Innocuous Presence
Free Council mages have always liked to study the spells of the Atlantean orders, but those societies usually don’t like upstarts meddling in their business. Hence, councilors resort to this spell to hide their surreptitious observations or even manipulations. Other orders also find use for this spell, such as the Guardians of the Veil in their ongoing efforts to police the practice of magic.