Of all the video game bad guys I’ve faced–the Bowsers, the face-huggers, the Giygases, it’s the passive-aggressive homicidal A.I. GLaDOS from Portal and Portal 2 that still gets to me. The final scene haunted my dreams for months after I beat the first Portal. Even just hearing her make fun of me in Poker Night 2 throws off my whole game.

None of this is a complaint; I love GLaDOS. Who doesn’t? Some of the most iconic moments Portal were provided by her haunting singing in “Still Alive” and the Turret Opera. But back in 2004, Valve didn’t originally set out to create such a memorable character. They thought they were bringing in veteran actress Ellen McLain for some quick voiceover work.

But with her decades of opera and live theater experience, Ellen made the AI into an integral part of the Portal world, not to mention a role that would win her multiple awards. Ellen encouraged them to develop GLaDOS’ simmering lunacy, as well as her ways of messing with the player’s head. She says her favorite line in the game is, “Killing you and giving you good advice are not mutually exclusive.”

Valve didn’t know didn’t know she could sing at first but when the team found out she is a trained soprano, the hustled to find a way to fit a song into Portal. Ellen has also played the voice of totalitarianism as Combine Overwatch in Half-Life 2 and the AI voice of Pacific Rim’s mecha Gipsy Danger.

Ellen and her husband, fellow voice actor John Patrick Laurie love making the rounds at conventions, where they’ve been known to sing GLaDOS’ signature song with him on banjo when asked. They say they love conventions and festivals because they are “treated like grandparents.”

She told Vice Motherboard in 2015, “I would play GLADoS forever.”
It seems like Valve would love that. Ellen-as-GLaDOS is even the offical Valve voicemail. Ellen will be one of the many guests at MAGFest, so make sure you stop by. If you’re lucky, maybe you’ll get to hear GLaDOS herself sing “Still Alive.”