Sarah Michelle Gellar mourned the death of “Buffy the Vampire Slayer" co-star Michelle Trachtenberg in an Instagram post.

Trachtenberg, who co-starred with Gellar on the hit TV series, was found dead in her apartment on Tuesday. She was 39.

Cast members of "Buffy the Vampire Slayer," "Gossip Girl" and more are remembering their co-star Michelle Trachtenberg​ after ...

Michelle Trachtenberg’s former “Buffy the Vampire Slayer” costar Sarah Michelle Gellar is looking back at their time together ...

Sarah Michelle Gellar is paying tribute to her late "Buffy the Vampire Slayer" co-star Michelle Trachtenberg after her tragic ...

Sarah Michelle Gellar has paid tribute to her former Buffy The Vampire Slayer co-star Michelle Trachtenberg following her ...

Gellar is honoring her late 'Buffy the Vampire Slayer' costar, who died on Wednesday, February 26, with a powerful quote from ...

Sarah Michelle Gellar paid tribute to the late Michelle Trachtenberg after the actress died at age 39.

Actor Sarah Michelle Gellar paid tribute to her “Buffy the Vampire Slayer” costar Michelle Trachtenberg on Thursday, a day ...

Gellar's tribute to her late costar echoes a monologue she delivered in the supernatural drama's season 5 finale.

Several actors, including Blake Lively and Melissa Joan Hart, have paid tribute to Trachtenberg after she died on Wednesday.

Fans of Buffy the Vampire Slayer will recognize the caption as a reference to a beloved quote from the show, spoken in the ...