You create a discordant blast of energy that disrupts the target’s available magic and transfers knowledge of that magic to you.
If the target prepares spells, it must choose one of its prepared 3rd-level spells, which is immediately lost. If the target has no 3rdlevel spells prepared, it loses a 2nd-level spell it has prepared. This progresses down to a 1st-level spell if the target has no 2nd-level spells prepared, and this spell has no effect if the target also has no 1st-level spells prepared. If the spell is on your spell list, you can cast this lost spell (using your caster level) on your next turn.
If the target is a spontaneous spellcaster, it loses one of its available 3rd-level spell slots. If the target has no available 3rdlevel spell slots, it must lose a 2nd-level spell slot (progressing as above). Randomly select one of the target’s spells known of that spell level; if that spell is on your spell list, you can cast it (using your caster level) on your next turn.
You must provide any focus or material components to cast the stolen spell.
If the target has more than one spellcasting class, choose one at random to be affected. This spell has no effect on spell-like abilities.
Any spell or spell slot lost because of this spell is treated as if the caster had failed a concentration check while trying to cast—the spell or spell slot is wasted and has no effect, but it is recovered normally the next time the character prepares spells or regains spell slots.
Pathfinder Roleplaying Game Monster Codex © 2014, Paizo Inc.; Authors: Dennis Baker, Jesse Benner, Logan Bonner, Jason Bulmahn, Ross Byers, John Compton, Robert N. Emerson, Jonathan H. Keith, Dale C. McCoy, Jr., Mark Moreland, Tom Phillips, Stephen Radney-MacFarland, Sean K Reynolds, Thomas M. Reid, Patrick Renie, Mark Seifter, Tork Shaw, Neil Spicer, Owen K.C. Stephens, and Russ Taylor.