Board Thread:WARNING - SPOILERS AHEAD/@comment-11593970-20130706054527/@comment-10759846-20130727155841

 If you read the synopsis for the next episode no matter what site most of them say something like this  The Girl Who Knew Too Much: As Allison begins to suspect someone dangerously close to her may be involved in the murders, Scott and Stiles conclude that Lydia’s rising talents may be their best bet to solving the murders.

Meaning the Darach is someone close to Allison either her family or friends.

Lydia being used to help figure out seems like she isn't it and is something else, Scott and Stiles don't make sense at all so I rule them out.

This leading me to ask who else is "close" to Allison which leaves me with only Gerard,Peter,Kate and Victora. I've read and heard Jeff Davis say someone would be brought back to life this season so that leads me to likely think its Kate or Victora.

Much like the Kanima I don't think the Darach knows who it is and is being controlled in the end Deucalion will behind it all.