Vampire Diaries Season 1 Episode 20 (Vampire Diaries s01e20) with title “Blood Brothers” airs on Thursday, April 29th 2010 at 08:00 pm via The CW Network. In this 20th episode, you can watch while Stefan struggles to come to terms with his past, both he and Damon reveal parts of their history to Elena, until she finally learns the truth about how they became vampires. Pearl has an ugly confrontation with Johnathan Gilbert.