The Vampire Diaries Season 5 Episode 11
500 Years of Solitude
The 100th episode of The Vampire Diaries featured brief returns by Jenna, Vicki and Alaric. The former was seen in Katherine's dreaming state, while only Bonnie and Jeremy could see the latter two.
Most of the installment centered on Katherine's fate. It looked like she would be a goner, until Nadia taught her how to travel into someone else's body and helped along the way by trapping Stefan and Elena and taking their blood.
The episode closed with Elena forgiving a dying Katherine... and Katherine then magically switching bodies with Elena. It looks like Katherine will be impersonating Elena going forward.
Oh, and Klaus came back and had sex with Caroline! This could be a problem down the line because Tyler also returned.