"Heartless"

Only thing i can think of is....

I have a horrible theory.  Mr. Douglas once said in class about how you can take an ordinary weak thing and add power to it.  Mr. Douglas is an Alpha, an Alpha needs a pack to gain power.  What if he's turning Corey into his pack member? Corey is the key to helping the ones who were taken by the Riders.  He can see them, and I bet he can see rifts where they come in and out of worlds.  Now even though he disappeared by a Rider's whip, i don' think he's with Stiles, but next weeks episode might answer that.