You bottle raw chaos in a small area, creating a hazard that goes unseen until an enemy steps into it.

Encounter   ✦     Elemental, Zone
Minor Action      Ranged 10

Target: One square

Effect: The target square becomes a zone that lasts until the end of the encounter or until an enemy enters it. Without a Perception check (DC 10 + your level + your highest ability modifier), your enemies notice neither the zone nor your use of this power. When an enemy enters the zone, that enemy and each creature adjacent to the zone take 5 damage and fall prone.

Published in Heroes of the Elemental Chaos, page(s) 53.