VD, S3-E17: Break On Through

Sage double crosses Damon this week, making him believe they are on the same side - track down the source of the White Oak, but only use it to kill Rebekah because Sage is in love with Finn - when she actually set him up just to get the information she needed:

The town's bridge is made of that white oak. She then passes this information on to Sage, who burns it down...

... but Damon secretly swipes a sign from it and ends the episode by telling Stefan: Let's go kill some Originals.

ELSEWHERE:

- Alaric tried to kill Meredith because he can be a psycho even without the ring on. Stefan and Elena also come across evidence that he's been collecting photos of his victims and even wrote a letter to Jeremy including a hit list of counsel members.

- Bonnie casts a spell on Alaric force him to chill and not try any mire killing for now.

- Bonnie's mom leaves once again because she can't handle being a vampire and thinks her daughter is better off without her.

Source: TV Fanatic