Tanya Martin and Brian Moser.

It seems that Tanya will have a key role in the season finale. I believe this will be related to her possibly discovering that Dexter is a serial killer. Because of this, Dexter would need to be protected—either by Harry, the more obvious choice, or by Brian, the more interesting one.

I think Brian would find out that Tanya was after Dexter and kill her before it became a problem, perhaps framing someone else for it.

What do you guys think about this? Would it be an interesting plot choice or just fan service? Well, at least for me, this theory is alright but least likely to actually happen.