Late-90s Kate, meanwhile, was in even more peril.
ENTERTAINMENT WEEKLY: How can my first question be anything but: What the heck is Marc’s deal?
Is he simply an emotional abuser, or is there more here and he has mental health issues?

Ron Batzdorff/NBC
Alcohol seems to be in play here as well.
ISAAC APTAKER:I think he definitely has some undiagnosed mental health issues.
Austin is doing such a good job.
I think he’s doing a really, really amazing performance.
But yes, Marc isroughin this episode.
We know that Kate’s family is concerned, but where is her head after everything that just happened?
First love, which can be blinding, but are the scales even beginning to fall from her eyes?
She’s really scared in that car.
She’s really scared when she gets left on the side of the road.
And then he turns and goes back to sweet Marc and he approaches her with a blanket.
And there is a big part of her that believes that she’s in love with him.
So it’s not so simple.
Let’s talk about this intervention that’s about to happen.
Like I said, a piece of her is aware that this is toxic.
But another, perhaps larger, part of her thinks, “This is the love of my life.
So it’s much more complicated than just going to save someone who knows they need to be saved.
It’s definitely a contributing factor.
There’s so many things going on inside of Kate.
But a first love is so formative and so shapes the way that you see yourself.
We’ve seen Toby’s lifelong struggle with his own mental health and with depression.
And Toby has had a much harder time with that.
And I think certainly in his history and struggle with depression could be a big factor there.
Yes, we will be with Toby next week.
It’s a really beautiful father-son story with Toby and the baby.
While Toby and Kate bottom out, Rebecca and Kate have never been stronger.
Had they just reached a new level of intimacy?
Rebecca was feeling closer to her daughter than ever.
I also think that she’s been wanting to tell Kate.
This weekend is a road trip with her daughter.
It felt like the right moment for her to share it.
Next week’s episode is set at the cabin in both the present and the past.
But we’ll definitely see some of the beginnings of that next week.
And how would you describe the emotions that we will see in the present-day cabin story?
Is it explosive in a different way?
Kevin is now the only Big Three member who doesn’t know about Rebecca’s issue.
We’re led to believe that the fracture between Kevin and Randall at least partially involves this issue.
There is much more of the story that we don’t know.
What were the conversations like in the writers' room about Rebecca being invigorated by her diagnosis?
This might be the most optimistic we’ve seen her since before Jack’s death.
Mandy’s found this whole new color to the older Rebecca character.
“You’re fat, I’m ancient, we’re gorgeous, let’s go swimming!”
How did that come about, and what were Mandy and Chrissy’s reactions to that bold line?
That’s all of our favorite line of the episode.
“This is who we are, Kate.
It’s so surprising, but I think it’s exactly what Kate needed in that moment.
Let’s talk about how that karaoke scene and song selection came to life.
Fans have been asking for a duet for a while.
Was that something that Chrissy and Mandy had been talking about on set too?
So they know it’s something people have really wanted.
It’s nice to see Jack directly recognize that at the end of this episode.
And we’ve hinted that in less direct ways before.
But there were many, many years after he was gone where it was really Rebecca.
And this week sets up our next episode where she really is a hero.