Barrow possessed by Void?
In episode 3×15 “Galvanized” we’ll meet a convicted killer called Barrow. He escapes while in surgery and Scott and the gang decide to find and help Barrow’s target.
This has to be linked to the overall storyline for this season, so either Barrow is a hunter who was caught in the act or he’s a killer who’ll agree to anything to escape and carry out his unfinished business. The latter is the cooler option. Either way, he knows about werewolves since he obviously knows of their weakness to electricity.
Agent McCall speaks to Scott about Barrow – “A mass murderer is bad enough. A mass murderer being controlled by someone – far worse.”
The way Barrow rises from the operating table and the crazy look in his eyes as he holds onto the live electrical table makes me think that he’s literally not in control of his body or actions. (Also it makes me wonder if Agent McCall knows more about the Supernatural than he lets on.)
What if while on the operating table, Barrow ‘dies’ for a moment – he could drift into the White Room (which really needs to be given a name) where he stumbles onto the nemeton or meets Void and given a chance to return to the world… at a price. He has to act as Void’s or an unknown demonic spirit’s avatar.
Also, I think Harris and Barrow used to know each other because Harris somehow always has a history with the bad guys.