It is dark by the time Abby and Bonnie meet with the hybrid. As they're getting out of the car, Abby tells Bonnie that Jamie will kill himself, if Bonnie doesn't give up the location of the coffins. This alone, does not sway Bonnie, who explains to her mother that this situation is bigger than any of them. The hybrid is standing a bit away from them, so as Abby continues to plead her case, she stealthily types a text into her phone that reads, "Warn your friends." So while it is not shown on screen, it seems that Bonnie texts Damon (and probably Elena, and maybe even Stefan) before giving up the location of the Original caskets.
Abby's Abode: As Elena tries to break free, she talks to Jamie to find out exactly what else he was compelled to do. He is supposed to kill himself, if Bonnie doesn't give up the location of the coffins. He's also been compelled not to hurt Elena. Elena is back to her fierce self, so she tells Jamie the ropes are hurting her wrists. That's my good, smart girl. When Jamie gets close enough to check on her, she breaks free, grabs his shotgun and knocks him out. Yay! No damsel, this week. She rushes to Stefan's side and asks what she can do. He tells her the wood is scraping against his heart. He needs her to remove it.
Which House Witch House: Damon enters the cellar of the Witch House, to find the coffins are gone. Klaus comes in after him. "What took you so long?" We cut to commercial. After the break, Klaus says, "Hiding behind your witchy friends..." He surveys the basement. "...And in squalor, no less." The 100 dead witches do not take kindly to Klaus's criticism of their domestic arts. The candles flare, and Klaus is brought to his knees, with a mystical migraine. Damon smirks. "Insulting a bunch of dead witches? Not smart. I made the same mistake, the first time I came here." Klaus's voice is strained. "The funny thing about witches -- is that living or dead -- they care about their own." He hits the floor with his hand and growls, before he continues. The witchy whispering starts up and it sounds particularly angry. Klaus talks over it. "A hundred dead witches have a thousand living descendants." Are they counted in the Census? Sorry, I just... Yeah. Klaus raises his voice. "I have no problem, killing every last one of them, if I don't get my coffins back." He's finally back on his feet. "As we speak, my hybrid friend is prepared to end the Bennett line." The whispering stops. The candles dim. Klaus closes in on Damon and says, "Now..." He looks toward the ceiling. His voice is soft and he forces himself to be polite. "Please, show me the coffins." And there they are. One. Two. Three. Oh, but no Four. Burn.