Dark Matter Season 2, episode 4: Why does Daniela leave?

While there's still been plenty of world-hopping, Dark Matter Season 2 has added an element of psychological family drama to its sci-fi mix.

In short, the Dessens are struggling. And while the family of three have tried their best to settle into something resembling a normal life, episode 4 suggests that dream is still a long way off.

So, what happens, and why does Daniela (Jennifer Connelly) leave at the very end? We've unpacked it below.

What happens at the end of Dark Matter Season 2, episode 4?

After sending Charlie (Oakes Fegley) off to college in a version of Chicago where technology is a long way behind that of "our" world, Jason (Joel Edgerton) and Daniela sit in their suddenly too-quiet apartment drinking tea. But it's not long before Daniela starts to share something that's troubling her.

"We're not the people we used to be," she says. "I guess it was crazy to think that we could be. I think you feel it too. It's... something's wrong with me."

Jason asks her what's going on, and Daniela alludes to the hallucinations she's been having ever since they came to this version of Chicago.

"It's like I'm being followed," she says. "And I keep thinking I see these versions of you. But... it's something else. I'm scared of things that I see in you. But I don't know what to do with what I've done."

When Jason asks what he can do, Daniela says there's nothing.

"I think I need to go away," she finishes.

The episode ends with her leaving — going where, exactly, we don't know — while reassuring Jason that they'll always be each other's person.

Why does Daniela leave?

It seems pretty clear at this point that most of the characters who've used the Box to travel to other versions of reality are suffering varying degrees of psychological damage as a result. Amanda (Alice Braga) has already confessed to Ryan (Jimmi Simpson) that she's experiencing a form of PTSD from her time travelling between realities with Jason in Season 1. And given that she herself is a psychiatrist, it seems likely that her diagnosis is correct.

Daniela, meanwhile, has not just travelled between realities; back in Season 2, episode 1, she even had to kill another version of her husband, who'd tracked the family to the world they were living in and who may have posed a threat. If travelling between worlds can give you PTSD, what does killing someone who looks exactly like your husband — who essentially is your husband — do to your mental health?

Probably not great things, as is evidenced by Daniela's increasing paranoia in Season 2. It's also complicated by the fact that she lives with a constant reminder of the person she shot dead. All of which is to say, Daniela's decision to leave the Dessen household in order to try to get better actually makes quite a lot of sense.

Will she be gone for ever? Almost certainly not. What she says to Jason before she leaves makes that clear enough. But perhaps she'll go on her own journey for a few episodes in an attempt to seek help, and to heal from the many traumas she's suffered.

Dark Matter Season 2 is streaming on Apple TV, with new episodes dropping every Friday.