The Vampire Diaries is basically doing its own version of Buffy the Vampire Slayer's "The Body." But thanks to some genuinely razor-sharp writing and some strong acting from Candice Accola in particular, it's still incredibly moving and effective. Just check out this crazy-intense clip from last night's episode. Spoilers...
So yeah, Caroline's mom is dying of brain cancer, and there are no treatments. Caroline decided to give her mom some vamp blood, in spite of every character on the show pointing out the reasons it wouldn't work. She tested it on a random other cancer patient — who seemed to get better briefly, but then died and turned into a vampire with unstoppable Stage 10 cancer.
The above scene, where Caroline is basically hiding from her dying mom and planning the floral arrangements for her mom's funeral instead of facing her, is just good drama, straight-up. It gets to the heart of who Caroline is — she's an optimist, who will always believe that her latest crazy idea will work out. But she's also a "control freak," and she'd rather be planning a party than dealing with something that has no solution. And Caroline really doesn't believe her mom can forgive her.
Luckily, Liz Forbes gets saved — although the show yanks our chain, big time, first — because Damon does a typical Damon move and gets Kai the psycho power-stealing witch to suck all the vampire magic out of Liz's body. And in another emotionally intense scene Liz makes Stefan promise to be there for Caroline, to help her move on after Liz is dead. The cancer is sort of a random, out-of-nowhere plot twist, but that's how it often is in real life as well. (Versus this show's frequent reliance on plot twists that are just plot twists.)
Also in this episode! Tyler wrecks everything. Basically. Liv and Luke try to convince their dad to let them avoid merging, but then Tyler decides to let Kai out of his drugged-out bed to — what? — convince the dad to be even more certain that Liv and Luke must merge immediately, instead. That's what gives Damon the idea of using Kai to suck the magic out of Liz. Later, Liv and Luke are merging after all, and Tyler breaks that up, bushwacking Liv's dad. And that's what leads to Luke trying to merge with Kai... and dying, leaving Kai as the new Boss Daddy of Magic.
I was actually kind of expecting Luke to win the merge but take on Kai's characteristics, thus becoming a psycho. Mostly, I'd rather see Psycho Luke than more of Kai, partly because Luke was gay and the show never did anything with that.
Oh, and Elena and Damon make some kind of undefinable progress (regress?) in their relationship, which has reached that state where going in circles is indistinguishable from going forward.
But the Caroline/Stefan stuff is really powerful, and if the show plays its cards right, I could see them becoming the new emotional core of the series.