Character Analysis
From the time the vamps first work out that Barry is buying silver bullets, they figure this dude might be a little dangerous. But oh, if they only knew…
When they meet Barry at his place in the outback, they see "a short, weathered, nuggetty man aiming a rifle directly at Dave's ear" (11.100). Which is to say, Barry's a dangerous fellow who has no compunctions about using violence to get what he wants. Luckily, he doesn't actually shoot them, but rather locks them up and plans to kill them later. He sounds like a nice fellow, eh?
The more the vampires see of Barry, the more frightening he is: "his broad shoulders, big hands, and broken nose were intimidating—as were his scars, and his empty blue eyes" (11.103). And indeed, Barry won't hesitate to resort to violence. He crafts a plan to kill Father Ramon and Nefley, making it look like a suicide. Ugh.
Unlike Dermid, Barry's smart; when looking for werewolves, he masquerades as a youth worker and listens for news about unexplained livestock deaths. Then he swoops into town, acting concerned, and gathering intel on potential werewolf candidates until he can zero in and kidnap the unlucky candidate.
However, Barry's so goal-oriented that sometimes he misses things, like the fact that Nefley is actually clueless about who Reuben is, and that he's obsessed with the undead, and that maybe there was a reason those "corpses" vanished from the trunk of the truck. Call it tunnel vision, if you will—with his eyes on the prize, Barry misses some key details.
Barry is a spiteful and violent fellow at heart—he trashes Nina's mom's guest room when held captive there, leaving dents and holes and broken things all over the place. So we don't really feel too badly when his own son bites him and transforms him into a vampire. In Barry's case, it might actually be a bit of an improvement.