At the end of Episode 2.07 “Masquerade”, Damon seals Katherine in the tomb, but not before she tells him that Elena is in danger because she is a doppelganger.
What exactly is a doppelganger, and why would Elena be in danger because of this? Or is this simply another one Katherine’s lies?
Katherine appears to be the incarnation of evil. She is selfish, manipulative, and she kills at the drop of a hat. But I believe that Katherine’s behavior is based on her own desperation. She needs a werewolf, and she needs the moonstone – and she demonstrated that she was willing to do anything to get them. But why?
As I speculated previously in “Wither Rose?”, I believe that Rose is pursuing Katherine to get the moonstone back. Rose wants Katherine dead. Katherine is terrified of Rose.
And there is only one way to keep Rose from killing her – and it involves both the moonstone, a werewolf, and Elena.
It is the Doppelganger Effect.
According to legend (and information I discovered on wisegeek.com!), the real person and their doppelganger are forever linked – if one dies, so does the other. However, because a doppelganger is a “shadow”, there is one time when the danger of the shadow does not exist – and that time is during a full moon, because this is the only time when the real person does not cast a shadow.
If the doppelganger can “replace” the real counterpart for one cycle of the moon, that is if the doppelganger can live the life of the real counterpart for approximately a month – from one full moon to the next – their roles are forever reversed. And vice versa – if the real counterpart can replace the doppelganger for a full cycle of the moon, the doppelganger is eliminated forever.
And what else happens on a full moon? Anyone human bearing the werewolf curse turns into a wolf until the sun rises.
Katherine needs the moonstone because she needs a werewolf on her side. The way to get the werewolf on her side is to promise to remove the curse with the moonstone, as Katherine did with Mason. Presumably, she can offer Tyler the same deal.
Why does Katherine need a werewolf – especially since vampires and werewolves are mortal enemies?
Katherine needs a werewolf to kill Rose – or at least keep her at bay – until she can activate the Doppelganger Effect. Once she does that, she will have succeeded in taking over Elena’s life. And then, Rose will no longer have any power over her.
It also means that she will ultimately wind up with Stefan, as she claims she wanted all along.
However, the Doppelganger Effect works both ways – it is also possible for Elena to eliminate Katherine by replacing her for a cycle of the moon!
We saw at the end of “Masquerade” that Elena has been kidnapped by someone, and that someone is probably Rose. Rose knows exactly what Katherine is up to – and Katherine knows what Rose is up to. This is what Katherine was referring to when she told Damon that Elena is in danger because she’s a doppelganger.
What Katherine did not say- because she is, after all, Katherine – is that she is also in danger – more danger than being locked in a tomb forever. She’s in danger of being eliminated!
I believe that Elena has just become a pawn in a game of chess between two ancient vampires.
Who will win? I have me theories, but they are only speculation….