The Vampire Diaries Season 2 Episode 5 (The Vampire Diaries s02e05) with title “Kill Or Be Killed” aired on Thursday, October 7th 2010 at 08:00 pm via CW Network.
Here is summary for The Vampire Diaries Season 2 Episode 5 :

Tyler learns more about the Lockwood family curse from Mason. Stefan and Damon argue over how to handle Mason.Elena tries to keep Jeremy from becoming more involved with the Lockwood mystery, but Jeremy makes an effort to hang out with Tyler. Mason gives Sheriff Lockwood some startling information, leading to a night of violence, confession and heartbreak.