There is zero chance Bonnie is actually dead, right? I feel like this is just trying to teach her some kind of lesson to stop playing with dark magic.
Elena is still busy being obsessed with killing Katherine. She won't be talked out of it, but no one will tell her where Katherine is.
And where she is, is magically linked to Bonnie. Bonnie is doing the spell to drop the veil. And she needs Katherine near her for some reason (I cannot remember why). However, while Bonnie is concentrating, Katherine hears a noise and goes to investigate. And it's Elena who starts attacking her. But, since she's magically linked to Bonnie, she's getting attacked as well. Eventually, Stefan shows up and stops her claiming that if she kills Katherine, she also kills Bonnie.
Bonnie manages to complete the spell and the dead supernaturals start coming back. Not many of them, but enough. Alaric is being cool with Damon and they are hanging out. I miss him. Kol is busy trying to kill Elena for her part in his death. Grams is back explaining to Bonnie that she has the power to take down Silas. And Jeremy is back getting a proper good bye with Elena.
However, Bonnie's plan to talk to Qetsiyah' and get her to tel her how to take down Silas doesn't work. Turns out, Silas knew about it the whole time and she's not smart enough or powerful enough to defeat him. Then he makes her think she's suffocating and leaves her there. Grams convinces her she's fine and Bonnie manages to do the spell that turns Silas into stone. Damon and Alaric plan to drop him in the middle of the ocean.
The veil has to be brought back up though. She tries to wait as long as possible to give Elena and Jeremy as much time to say good bye as she can. But, once she's back down in the cave, she decides to use her magic to keep Jeremy alive. Grams tells her, begs her not to, but Bonnie will not be denied. Until she is. Doing the spell apparently kills her. She collapses while doing the spell and when she 'wakes' back up, Grams is there telling her she died trying to complete the spell.
Oh, and outside the bar, Matt and Rebekah run into her ex (the vampire hunter from, like, a thousand years ago or something). And I'm pretty sure he's here to kill her. Maybe this is the thing that somehow prompts her to head over to New Orleans with her brothers. π€·ββοΈ