The Vampire Diaries - Season 7 Episode 10
Hell Is Other People

After finding himself on the wrong end of Julians plan to avenge Lilys death, Damon awakens to find himself trapped inside the Phoenix stone, tormented by a traumatic experience from his time in the Civil War and forced to face his darkest demon in order to get out. On the outside, Bonnie is in a race against the clock to get Damon out before the effects of the Phoenix stone take over and leave him changed forever.