pf2e.fyi
From Pathfinder Impossible Magic, which isn't enabled.

Emergency Targe

FEAT 4
Activity reaction
Prerequisites sparkling targe hybrid study

Trigger An enemy you're aware of hits you with a Strike or a spell attack, or you fail a save against an enemy's spell.
Requirements You are wielding a shield or have the Shield spell prepared.

You immediately Raise a Shield or cast shield. The circumstance bonus applies to your defenses when determining the outcome of the triggering attack or spell.

Pathfinder Impossible MagicORC