<Tr> <Th> 39 </Th> <Td> 17 </Td> <Td> "Know Thy Enemy" </Td> <Td> Wendey Stanzler </Td> <Td> Mike Daniels </Td> <Td> April 7, 2011 (2011 - 04 - 07) </Td> <Td> 2J5267 </Td> <Td> 2.73 </Td> </Tr> <Tr> <Td_colspan="8"> Elena and Alaric become angry with John when Isobel's arrival devastates Jenna . Alaric is abducted by Maddox, a warlock from Klaus's inner circle . Meanwhile, Bonnie works with Jeremy and Damon to find the spell they need to gather the power of the witches killed in the massacre . Damon takes them to the site where the witches were burned . Matt demands to know what happened to Vicki . After Caroline tells him and then compels him to forget, it is revealed that Matt's involvement was a setup by Sheriff Forbes to find out everything about the vampires . Matt has drunk vervain, so the compulsion does not work . Isobel kidnaps Elena and then receives a phone call from Maddox, who tells her that she has finished what Klaus compelled her to do and is free to let Elena go . Isobel apologizes to Elena for being a disappointment as a mother, removes her necklace, and burns to death in the sun . Stefan and Damon realize that Bonnie is their new secret weapon since she now has tremendous power . Jeremy is upset because, if Bonnie uses too much power, she will die . Katherine, who had been set up by Isobel and taken by Maddox, wakes up to see Klaus take control of Alaric's body . </Td> </Tr> <Tr> <Th> 40 </Th> <Td> 18 </Td> <Td> "The Last Dance" </Td> <Td> John Behring </Td> <Td> Michael Narducci </Td> <Td> April 14, 2011 (2011 - 04 - 14) </Td> <Td> 2J5268 </Td> <Td> 2.81 </Td> </Tr> <Tr> <Td_colspan="8"> Klaus (in Alaric's body) compels Katherine to tell him how the others plan to kill him . He then finds out that Bonnie has obtained power that could threaten his life . At the school dance, Jeremy confronts Bonnie about why she wants to kill herself for Elena, and Damon overhears . Jeremy goes to Stefan for help, and Stefan tells Elena about Bonnie's plans . Elena finally guesses who "Alaric" really is . Bonnie fights Klaus with her powers and appears to die . As Elena grieves, Damon tells her that Klaus must believe Bonnie is dead, but her death was faked . Realizing that Bonnie intends to endanger herself to defeat Klaus, Elena pulls the dagger out of Elijah's heart . </Td> </Tr>

Who dies in season 2 of vampire diaries