Paul Wesley, Ian Somerhalder Paul Wesley, Ian Somerhalder

When The Vampire Diaries flashed back to the early 1900s to explore Stefan's ripper origins, Damon was very much absent from his brother's life. When the CW series travels to that era again, viewers will see exactly how the rift between the Salvatore boys was created.

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"You start to see the rebirth of Damon Salvatore and where he was in 1912," Ian Somerhalder tells "You learn a lot about the dynamic of Stefan [Paul Wesley] and Damon and how it changed."

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Although the pair has had more than a century of ups and downs, Somerhalder is confident that the strength of their brotherhood outweighs their differences — even the ones that involve a certain brunette named Elena (Nina Dobrev). "These guys could've killed each other a hundred times and they can't. They just cannot end it," he says. "They're the only two that know each other and understand each other ... and at the end of the day they do love each other and they have to take care of each other."

The Vampire Diaries returns with new episodes on Thursday, March 15 at 8/7c on The CW.