Spoilers
So. Most recent episode.
There was a lot to like about it, but there are a couple of things that are still scratching at the back of my brain.
First: why didn't Claire tell the Winchesters what whatsisname told her: about the super-weapons that killed his pack and started him on the path of attacking humans? Even though she doesn't know where it fits in the puzzle, it seems like it would be important intel that she'd want to share with Sam and Dean.
Second: this episode seemed like a golden opportunity to advance the "what's up with Cas?" plot that they seemed to be hinting at at the end of last episode. Especially since Castiel would have provided an easy solution: he was able to keep Dean from turning into a Jefferson Starship when he was bitten by Eve, so beyond calling him because he cares about Claire, it would have been a potential solution. And having him not answer would have been a big hint that something was up. Even if the writers didn't want Sam and Dean to be super-concerned just yet, it would remind the viewers that this was going on and is apparently a plot point?
Anyway, I'm glad Claire didn't die. (Every time a recurring character shows up, I'm worried, and that goes double if they're female.)
Also, it seemed to me like maybe Dean was relating it back to his own experience of the demon cure?