“I’m scared, and when I lose control bad things happen to people I love,” says Sophie Turner in a new trailer for “Dark Phoenix.” The “X-Men” pic sees Jean Grey (Turner) reeling in the aftermath of a mission in space that goes horribly awry. She’s nearly killed by a mysterious cosmic force that leaves her infinitely more powerful. But Jean’s having trouble harnessing that power, and it’s making her incredibly unstable — and a threat to her X-Men family, who fear that she’ll spiral out of control and kill them all.

Not everyone’s worried about Jean and her well-being. As the X-Men fight to save her soul, Smith (Jessica Chastain), a visitor from another planet, is determined to take advantage of her vulnerability. “You’re special,” she tells Jean. “Stop fighting that force inside you. Embrace it. You will possess the very power of a god.” And it’s that power that Smith hopes to exploit.

Jean Grey first appeared in 2016’s “X-Men: Apocalypse.” Smith is new to the franchise.

Best known for her role as Sansa Stark on “Game of Thrones,” Turner’s film credits include “Barely Lethal” and “Another Me.”

“Dark Phoenix” opens June 7.