You can direct a failed spell against a different target.
Benefit: Whenever a bouncing spell targeting a single creature has no effect on its intended target (whether due to spell resistance or a successful saving throw) you may, as a swift action, redirect it to target another eligible creature within range. The redirected spell behaves in all ways as if its new target were the original target for the spell. Spells that affect a target in any way (including a lesser effect from a successful saving throw) may not be redirected in this manner.
Level Increase: +1 (a bouncing spell uses up a spell slot one level higher than the spell’s actual level.)
Advanced Player’s Guide. Copyright 2010, Paizo Publishing, LLC; Author: Jason Bulmahn.