Using the momentum from your enemy's blow to fall back or slip to one side, you make a sudden retaliatory attack as he stumbles to regain his composure

Encounter   ✦     Martial, Weapon
Immediate Reaction      Melee or Ranged weapon

Trigger: An enemy makes a melee attack against you

Attack: You can shift 1 square, then make a basic attack against the enemy.

Special: Gain a power bonus to your basic attack roll equal to your Wisdom modifier.

Published in Player's Handbook, page(s) 105.