Ian Somerhalder would like to preface any conversation about the joy he finds in playing devious vampire Damon Salvatore with the following: “I am not a maniacal killer.”


But the 31-year-old does have a few things in common with his bloodsucker on “The Vampire Diaries.”


“Damon is a very lonely guy,” Somerhalder says. “And there are two relationships that he wants back — his brother and his girl. He’s doing all of this for love, strangely enough.”


The girl Damon aims to regain as “The Vampire Diaries” returns with new episodes tonight is Katherine, the one who turned him into a vampire in 1864 and was then killed. (His brother, Stefan, was also in love with Katherine, who happens to be the spitting image of Elena, Stefan’s present-day girlfriend.) Somerhalder has found that messy love triangle is one of the main reasons fans are tuning in — as well as writing surprising letters.


“Some of [the fan mail] are all questions: ‘What’s your favorite color?’” Somerhalder says. “But some of them ... they are really insightful and really sort of heartfelt. I mean, these young teen girls are so into the love aspect. They have so many questions about love. They’re not confused. They’re just so inquisitive about it.”