You declare the space in front of you to be forbidden, and any enemy that dares to enter it will suffer the consequences.

Daily   ✦     Martial
Standard Action      Close blast 3

Effect: The blast creates an area of forbidden ground. Until the end of the encounter, whenever an enemy enters the area, you or an ally can charge that enemy or make a melee basic attack against it as an immediate reaction.

Published in Martial Power 2, page(s) 91.