The Doppelgänger Prophecy is a thousand year old prophecy created by Esther Mikaelson. Tatia was the first doppelgänger to cause a war between Elijah and Klaus Mikaeson stringing them both along without telling Klaus she didn't feel the same. Eventually 500 years past and Katherine caused a more of a rift between the brothers when Elijah fell for her. Alex Gilbert, the final doppelgänger and she brought the Mikaelson Family whole again when she gave birth to Hope Mikaelson.
The Prophecy Throughout The Vampire Diaries[]
Season Two[]
In By The Light Of The Moon, Elijah speaks with Alex and tells her she's going to play a huge role in his families future.
In Klaus, Klaus asks his witch Maddox what the spell he's going to preform. Maddox said it'll show him some visions of the prophecy but he also told him that it could change over time and that it might not be 100% true. Klaus sees visions of him falling madly in love with her to see that she'll become a hybrid like him then a row of coffins with the Mikaelson crest on it.
Season Three[]
In The Reckoning, In the parking lot of Mystic Falls Hospital they share a moment before they kiss, sparking the prophecy and the love bond.
In Homecoming, Alex betrayed her friends to save Klaus' life because of the love bond that they share.
In Bringing Out The Dead, Alex attended a dinner with Damon and Stefan at the Mikaelson's to talk to Elijah and Klaus. When she heard the name Tatia she felt like that she was born to love Klaus and that he only liked her because they share the same face.
In Dangerous Liaisons, Klaus invited Alex to the Mikaelson Ball and got her a dress to wear. She saw his art room and she sees drawings of her.
In All My Children, Alex finds out that Esther is the one who created the prophecy and love bond. She also found out if Klaus dies she dies painfully.
In The Departed, Alex thought Klaus dies so she says her goodbyes to Elijah and Rebekah and then she says her goodbyes to Stefan over the phone.