Demons can feel Aether through a sensation dubbed “aetheric resonance.” The specifics of the feeling vary from demon to demon, to some it is like static, a slow uncomfortable pull, while others describe Aether as possessing a metallic scent or strange hue. All of the God-Machine’s most potent endeavors are dependent upon the conversion of Essence
into Aether. Angelic Numina, Influences, Manifestations and true forms, as well as facilities and stockpiles: everything emits Aether. Aetheric resonance serves as a valuable asset by which the Unchained may feel out the workings of their enemy. Fortunately for the Unchained, aetheric resonance is a uniquely demonic trait. Angels possess no comparable means by which they can flush out their fallen counterparts.
System: By expending a single point of Aether a demon can feel out Aether in the area around her for the remainder of the scene. Whenever a source of aetheric energy comes within the radius of her aetheric resonance, including a demon, she immediately becomes aware of the direction of the source and the quantity of Aether surrounding it. Storytellers should convey this feeling in narrative terms: “a massive energy source is approaching from due east” rather than, “twelve yards away an angel just spent three points of Essence.” Being in a Twilight state does not protect an angel from aetheric resonance, but demons hidden by Cover and angels masked by Infrastructure are not immediately revealed. This defense lapses only briefly when they expend Aether or Essence. Facilities register with particular intensity, thus the God-Machine frequently employs special masking devices, Aether-eating cryptids, and other oddities to hide its most critical projects.
Aether is an impersonal energy, identical in feeling regardless of origin. Aether emerging from an active facility feels no different to that of angelic Numina or the demonic form.
Aetheric resonance can never grant specifics about a source of Aether, making it a poor judge of whether an Aether source is friend or foe. Also, the exotic powers of cryptids and stigmatics do not emit Aether despite their origin and therefore do not register to aetheric resonance.
Aetheric Resonance Radius
Primum 1–2: 5 yards, same room, small apartment.
Primum 3–4: 50 yards, multi-story home, concert hall
Primum 5–6: 500 yards, office complex, entire city block
Primum 7–8: Half a mile, skyscraper, entire neighborhood
Primum 9–10: A mile or more, a sprawling industrial complex or massive estate