“It’s going to continue to be tough for Kiesha,” says Baker, 28, as the Showtime series heads toward its Aug. 23 season finale. “She’s not the same person she was in Seasons 1 and 2 and in the first episode of Season 3. Finding her was the first step in a whole new process of dealing with a new person.

“Her family is so happy to have her back but they didn’t experience the things she did,” she says. “It’s something no one can fully understand.”

Kiesha was preparing to leave the South Side of Chicago for college when she vanished from a bus stop — and from “The Chi” — for three episodes. While her friends and family searched for her, fearing the worst, viewers eventually learned she was being held hostage in the basement of a local psycho, Omari (Cedric Mays), who kept her chained to a bed in his basement lair.

“At first I didn’t know [the storyline],” says Baker. “They called me a month and a half before we started to shoot. They needed to make some changes to the show … and decided to take on the subject of missing black girls. All I knew was that [Kiesha] was going to missing. In real life, I can go on social media and go through the feeds right now and see at least three faces of missing people.”

Baker says the scenes in Omari’s basement were shot chronologically.

“It was important for me not to be in a few episodes to build up the suspense and to see how the community reacts while Kiesha is missing,” she says. “Once we got down to that basement I loved shooting those scenes in order … to experience what the character was going through. It helped to make it a little more realistic in my head.

“We didn’t communicate much,” she says of herself and Mays. “I remember he just kept asking me after every take, ‘Are you OK?’ I appreciated him checking up on me as an actor, but since I was playing Kiesha it really didn’t help.

“I said, ‘I’ll let you know when I’m not OK’ and he stopped asking me.”

Kiesha was finally freed when Ronnie (Ntare Guma Mbaho Mwine), who suspected something amiss with creepy Omari, broke into his house and pried off the lock to Kiesha’s prison — while she battered Omari with a tire iron (killing him).

“That was one for all the girls out there who’ve experienced what Kiesha experienced,” Baker says. “That was a victory. I remember [episode director] Jet Wilkinson telling me ‘We have to give these girls hope — take back the power and go to town on him.’

“If anybody is ever in this situation, maybe they will remember they saw someone fight through it.”

And, Baker says, her on-screen experience made her more aware of its real-life parallels.

“I didn’t know how many women are taken every day. It blew my mind,” she says. “Most of the time the demographic of the woman lines up with the demographic of the person taking her. So with black women, it’s been shown that mostly black men have been taking them. There were just so many little details I didn’t know that come with all of this.

“I am a mother, so it set an alarm off inside of me of how many girls are being taken,” she says. “The show has really helped me to find what interests me. I’ve teamed up with the [non-profit] Black and Missing Foundation and I want to continue to do this work, even after the season is over.

“It’s very important.”