You make your foe pay for their miss by slamming them with your shield.
<php>echo “<b>Prerequisites:</b>”;</php> Weapon Mastery (Close-Quarters)
<php>echo “<b>Benefit:</b>”;</php> You may make an attack of opportunity with a shield against a foe who misses you with a melee attack. Resolve your attack of opportunity after your foe’s attack. You may only make one attack of opportunity in this manner per round.