<Tr> <Td_colspan="8"> Seen in flashbacks ranging from 2007 to 2009, high school students Elena, Bonnie and Caroline are decorating the school Christmas tree and enjoying a simpler time . In the present day, Kai kidnaps Jo and with Liv and Luke's help, he locates the knife where Jo had hidden her magic and forces Jo to take it back by stabbing her, but she tells him that for that to work she has to be willing to do it because she put it there also willingly . Luke leaves saying that he does not want to be a part of Jo's murder . Jo tells Kai that she may bleed out if he does not do anything and that all his efforts will be vain, so he leaves to go fetch some bandages and leaves Liv with the mission to find a way to give Jo her magic back . Meanwhile the sheriff is brought to the hospital where it is revealed that she has a tumor on her brain, and Stefan says to Caroline that she will die because vampire's blood cannot heal her . Jeremy and Matt trap Enzo with the intent of killing him but Matt wants to kill him slowly, which Jeremy finds a little harsh but Matt is determined . Liv tries to convince Jo to take her magic telling her that she may be able to beat Kai in the merge because of how well she has done without magic for 18 years . Kai comes back and tries to kill Liv which forces Jo to take back her magic . Damon and Alaric came to the rescue to find out that Jo has her magic back . They trick Kai and send him out of border where Alaric puts a gun on his temple but Jo comes out and asks him not to kill him because she might be able to beat him in the merge, and that she needs a little time to get strong . They chained him in Mystic Falls where he cannot use any magic but after a while, Kai drains the magic from the travelers' spell, something that also breaks the spell surrounding Mystic Falls . Matt brings Enzo past the border of Mystic Falls but Enzo cannot die due to Kai absorbing all the magic . Enzo turns on Matt telling him that he will let him live if he helps him take away all things that makes Stefan happy . Damon and Stefan come back to their home in Mystic Falls, and when Elena arrives, Damon cannot see her because of Kai's cloaking spell . Kai kidnaps Elena . </Td> </Tr> <Tr> <Th> 122 </Th> <Td> 11 </Td> <Td> "Woke Up with a Monster" </Td> <Td> Paul Wesley </Td> <Td> Melinda Hsu Taylor </Td> <Td> January 22, 2015 (2015 - 01 - 22) </Td> <Td> 2J7861 </Td> <Td> 1.63 </Td> </Tr> <Tr> <Td_colspan="8"> Kai has captured Elena and holds her as hostage in the Mystic Grill after killing the owner . He plans to practice his new found abilities on Elena to master his new magic . Meanwhile Caroline and Stefan start to look for a doctor who could cure Liz, and get to Duke . On the way Stefan goes to the art exhibition held by his niece, the true Sarah Nelson, but he is followed by Enzo . Kai brings Elena to high school and melts her daylight ring . Elena manages to escape Kai and phones Damon who comes with Liv to save her . However, Liv is abducted by her brother, Luke who comes to take her home . Needing a witch to perform a cloaking spell, Jo steps in to help Damon and they both enter the building . They manage to save Elena but Jo is becoming weaker and Kai spots them all . Meanwhile, after learning from a doctor that her mom has no treatment, Caroline decides to inject her blood to another cancer patient . The aftermath is a well - looking person who seems to have defeated the tumor . The patient is feeling alright again so Caroline and Stefan rush back to Mystic Falls . In the school, Kai tricks Damon to stab Elena and goes after Jo . Alaric and Jeremy come in to save Jo just in time and they decide to keep Kai under sedative . Once back home, Caroline reveals to her mother that only vampire blood can heal her and puts some in her tea . The episode ends with the patient slowly dying in a brutal way, just while Liz is drinking Caroline's blood, with whom she now believes can be saved . </Td> </Tr> <Tr> <Th> 123 </Th> <Td> 12 </Td> <Td> "Prayer for the Dying" </Td> <Td> Jeffrey Hunt </Td> <Td> Brett Matthews & Rebecca Sonnenshine </Td> <Td> January 29, 2015 (2015 - 01 - 29) </Td> <Td> 2J7862 </Td> <Td> 1.47 </Td> </Tr>

When does caroline turn his humanity back on season 6