THE VAMPIRE DIARIES Season 2 Episode 6 : Plan B
Though Liz accepts Caroline, Caroline compels her mother to forget that she is a vampire. Bonnie incapacitates Mason by giving him an aneurysm; he is then questioned by Damon. Damon tortures Mason, who believes that Katherine loves him and refuses to talk. Damon tells Mason that Katherine is using him and he eventually kills Mason. Bonnie has a vision of the moonstone's location in a well. Stefan discovers the well is full of vervain, which burns him. Caroline and Bonnie help Elena rescue Stefan and retrieve the moonstone. Jenna is compelled by Katherine to stab herself. Elena, fearful of what else Katherine might do, decides to break up with Stefan for good. Needing another werewolf, Katherine compels Matt to attack Tyler, so that Tyler will kill Matt and become a werewolf.