You punch one foe, then spin and deliver a kick to another. Thunder rumbles in the distance, rolls closer, and explodes between your two foes.

Daily   ✦     Implement, Psionic, Thunder
Standard Action      Melee touch

Target: One or two creatures

Attack: Dexterity vs. Fortitude

Hit: 3d6 + Dexterity modifier thunder damage.

Miss: Half damage.

Effect: The first time either one of the targets takes damage during a turn, the other target takes thunder damage equal to your Strength modifier. This effect lasts until the end of the encounter or until one of the targets drops to 0 hit points.

Update (6/14/2010)
In the Effect entry, replace “When one of the targets takes damage” with “The first time either one of the targets takes damage during a turn.”

Published in Player's Handbook 3, page(s) 66.