Criminal Minds: Season 5, Episode 23

5 - 23: Our Darkest Hour

The BAU team hunts a serial killer in Los Angeles who preys on his victims in the dark, killing entire families except for one left alive to remember. The episode ends in a cliffhanger when Billy Flynn, the Prince of Darkness (Tim Curry) shoots and kills Detective Matt Spicer (played by Eric Close) before kidnapping his daughter, Ellie and fleeing the scene, leaving both Morgan and Spicer behind. Morgan then passes out seconds later and the scene goes to black with "To Be Continued" showing up on the screen.