Undeclared TVD - 3.11 and 3.12

Undeclared! The Vampire Diaries

Stefan and Klaus's game of Who's the Bigger Villain continues, and puts the lives of those we love at stake (though, not at a White Oak Stake): Stefan threatens to drive Elena off the bridge where her parents died after force feeding her his blood, and Tyler bites Caroline, infecting her with werewolf...venom? saliva? toxin? I don't know the specifics of what that is exactly, but it makes her very sick and in need of saving by Klaus. And boy does that saving end up being a Thing We Weren't Expecting.
Alaric seems to be getting involved with Dr. Meredith Fell, who may or may not be a murderer, but who definitely is in the know about vampires (she's a Fell, after all) and uses their blood to save people. Damon is protective of his BFF, and also overall awesome in these episodes.
Bonnie and Elena find Bonnie's long-lost mommy, who we pretty much hate, but Klaus has found her first, so it's a whole thing where Elena saves the day like a boss. Caroline's dad comes back to try to help Tyler break the sire bond, to varying degrees of success - he ends up almost dead but saved by vampire blood again. And Damon undaggered Elijah!