: Elena discovers that Jeremy has been hanging out with a "bad crowd," specifically a compelled Kol Mikaelson, who has been posing as his friend.
In this episode, Elena and Damon travel to Denver to check on Jeremy and use his ability to talk to the dead to identify their vampire bloodline. [S3E19] Drippin Episode
If you are referring to a different series, here are other notable Season 3, Episode 19s: : Elena discovers that Jeremy has been hanging
The Vampire Diaries Season 3 Episode 19 recap " specifically a compelled Kol Mikaelson