Caroline is woken up by Colin, the patient she gave her blood to. Stefan and Caroline learns that he has become a vampire. Liv and Luke's father arrives to celebrate their birthday. They propose him to avoid the merge because none of them wants the other to die. In the hospital, Caroline and Stefan realize that Colin is a vampire but is not cured of his cancer. The tumor expanded and while he is a vampire, he can still feel the pain of the tumor growing. Caroline's mom realizes that she will go through the same as Caroline fed her her blood. Jo suggests a full blood transfusion but it fails. Tyler, who now knows the twins are ready for the merge (as they are 22 years old), tries to wake Kai up, but is stopped by Damon. Kai helps Liz taking all the magic from her body but with the condition that the merge is set for that night. Meanwhile, Liz is having a heart attack and Elena is helping her. Mr Parker deceives the twins and begins to merge them, but Tyler comes just in time and hits him. Luke promises Liv he will come back and go and look for Kai. Kai and Jo begin the merge, although she is not ready yet. Luke stops the merge and convinces Kai to do it with him. Damon compels a doctor to save Liz's life, but she dies. Caroline arrives in that moment and cries on her mother's body. Before dying, Liz has a vision in which she sees her daughter with a bloody face, and then mysteriously wakes up. After the merge, Jo witnesses Luke and Kai fainting. While Jo is crying and holding her brother in her arms, he dies and she realises that Kai has won the merge.