Stupidity: Damon and Stefan are trying to get Elena's humanity back - they could have just asked Rebekkah or Klaus or Elijah to compel her to turn it on.
Continuity mistake: In the previous episode when Damon and Caroline sleep together Caroline's bra is dark pink, in this one when she wakes up her bra is blue.
Damon Salvatore: I DO believe in killing the messenger. Why? Because it sends a message.
Question: If Katherine/Silas are the ones who killed the hunter, that is Jeremy, why aren't they are cursed with the hunter's curse?
Answer: Silas did mention to Bonnie later that he was so powerful he was able to overcome Jeremy's hunter's curse in minutes.