Kenneth Mitchell was diagnosed with ALS in August 2018 and has been using a wheelchair since last October
Kenneth Davis
Credit: Chloe Aftel

Nearly two years after being diagnosed with ALS in 2018, Kenneth Mitchell is opening up about that life-changing day.

In this week’s issue of PEOPLE, the Star Trek: Discovery star, 45, and his wife, former actress Susan May Pratt, detail how they broke the news of his amyotrophic lateral sclerosis (or ALS, a debilitating neurological disease that slowly takes away a person’s ability to control his or her muscles) diagnosis to their two children.

After consulting experts on how to discuss the diagnosis with their daughter and son (Lilah, 12, and Kallum, 7), who were 11 and 5 at the time, the couple spoke to them separately.

“Our daughter asked, ‘Is papa going to die?’ ” recalls Pratt. “I was hesitant and said, ‘Well, we’re all going to die.’ She said, ‘But when I’m a kid.’ I said, ‘Well, it’s possible.’ She sat on his lap and cried.”

  • For more from Kenneth Mitchell, pick up this week’s issue of PEOPLE, on newsstands Friday
Kenneth Davis and family
Kenneth Mitchell, wife Susan May Pratt and their two children
| Credit: Chloe Aftel

Their son had a different (and somewhat humorous!) reaction.

“We were like, ‘Hey, Kal, we need to talk to you,’ ” says Pratt. “We didn’t want to talk about dying because he doesn’t understand that at 5. We told him that dad has an illness and we’re going to do everything we can. And he goes, ‘This is not what I came here to talk about.’ He thought he was in trouble!”

From that moment on, the family of four became more united than ever.

“We pulled the kids out of school and took vacations,” says Mitchell. “It took up a lot of energy and time just nurturing my relationships [with loved ones] and grieving with them.”

“The hardest thing about all this has been my kids,” he adds. “I want to be strong for them and keep inspiring them. I think kids are really interesting. They have such an innocence and a hope that other people don’t. I just draw on that a lot.”

Through the Valley of Shadows
Kenneth Mitchell in Star Trek: Discovery
| Credit: Russ Martin/CBS

In the months leading up to August 2018, Mitchell began to feel lethargic and was experiencing fasciculations, or twitching, in his left arm, though he didn’t think much of it.

“I thought it was from coffee or dehydration or something to do with the gym, but the twitching never went away,” he says.

While doctors initially suggested he was suffering from either a pinched nerve or multiple sclerosis (his mother has MS), they soon realized after further testing that he had ALS.

“It was like I was in my own movie, watching that scene where someone is being told that they have a terminal illness,” he says of hearing the diagnosis for the first time.

“The air left the room,” Pratt adds. “I couldn’t breathe anymore.”

Still, “there was something really simple and beautiful, in a way, about how we were in the trenches together,” says Mitchell. “And we mourned.”

Now, Mitchell, whose current shows (CBS’ Star Trek: Discovery, CW’s Nancy Drew, and Hulu’s The Old Man) are wrapped or on hiatus, says he’s cherishing every moment with his family.

“We aspire to live life to the fullest and seize each day,” says Mitchell, who has been using a wheelchair since October 2019. “I feel like I’ve done that. I think when you’re truly faced with death, you can really see that the highs are higher, the lows are lower, and you can move forward with a different zest for life. And that’s a gift.”