Board Thread:False Info and Speculative Discussion/@comment-24732895-20140731064438/@comment-25242503-20140731232515

If it is deaton, there's a perfect explanation for that: balance. He admitted that he's dealed with the power of the Nemeton before, and perhaps he intends to do it again, erasing the surplus of supernatural creatures it's atracted and empowered:  He is a druid, after all, and would be dealing with the problems a dark druid left in her wake.

About the recognition part it's easy to explain, too: he was the druid in the former Hale's pack, so it's perfectly possible he went into the vault a few times with Derek's mother.

But I don't think it's deaton: he never would leave Peter out of the list, unless he wanted to kill him all by himself ( after all, Peter killed the former- and most probably Deaton's chosen - Alpha, Derek's sister... and, what-the-heck is Peter: nobody likes him).