When you sneak attack opponents, you can also assault them with magic.

Prerequisite(s): Int 13, Quicken Spell, impromptu sneak attack class feature

Benefit: When you make a successful sneak attack against an opponent, by taking a swift action you can cast on the target any touch-range spell of 3rd level or lower that you have prepared (it need not be prepared as a Quickened Spell). You may use this ability a number of times per day equal to your Intelligence modifier, but no more than once per round.