When no allies are nearby, you can safely unleash the full extent of your fury.
Prerequisites
Rage special ability, base attack bonus +6.
Benefit
When you make a full attack with a melee weapon while raging, you can reduce the duration of your rage by 1 round to make one additional attack at your highest base attack bonus. When you use this feat, you suffer a -2 penalty to all attack rolls made this round and to your AC until the start of your next turn.
You cannot use this ability if there are any allies within 5 feet of you or of any squares you threaten.