She managed to shoot Quinn and take Garcia hostage before Reid caught up to her.
When faced with the opportunity to shoot her, however, a car drove up, revealing cult members holding Garcia at gunpoint.
In a shocking twist, the bad guy turned out not to be a guy at all.
In the finale, the BAU team spent most of the episode trying to figure out how missing FBI Agent (and wannabe profiler) Owen Quinn fit into a serial killer cult.