You loose missiles in an unpredictable pattern.

Daily   ✦     Martial, Weapon
Standard Action      Area burst 1 within 10 squares

Requirement: You must be wielding a crossbow, a light thrown weapon, or a sling.

Target: Each enemy in the burst you can see

Attack: Dexterity vs. Reflex

Hit: 2[W] + Dexterity modifier damage.

Miss: Half damage.

Published in Martial Power, page(s) 78.