First, a rebel faction of the OPA attacked Earth and Mars.
Now, they have attacked their own.
We spoke to showrunner Naren Shankar about the extraordinary Protomolecule extraction sequence and the decision to kill Fred Johnson.

Amazon Studios
He goes out in a different way.
And it was such a nice relationship that was building up with Fred and Holden over the season.
And it does ignite a number of other elements in the storyline.

Amazon Studios
And we brought back Bull, who wasn’t in season 3.
We bring Bull back into the fold.
So we did a little bit of rejiggering there, but I think it worked out really nicely.
And it was such a shocking, shocking moment when Fred gets killed.
It’s pretty wild.
I remembertalking with Chad when he got killed offonThe Walking Dead.
Chad’s been on the show for a long time and he’s such a pro.
And he goes, “Huh, I figured that.”
But he’s such an interesting character.
He was always straight with him, even though no one trusted him.
And anyway, yeah, that was a big moment.
And I imagine that was not easy to execute at all.That was not easy to execute at all.
The director, Nick Gomez, did a great job with that.
We sort of based it on … We sort of based it on that because it had a great unfolding capability.
And we just started developing that on the concept art side.
And if you look very closely, it’s a Savage Industries neck.
Adam Savage created that mech’s neck in season 3.
That scene was awesome.Yeah.
It’s a combination of so many different elements.
Those are always the trickiest to pull off.
That was one of the most complex sequences we did this season.
Switching gears, big Naomi and Marco reunion here.
I’m sure it was exciting moment for you as well.Oh, yeah.
The funny thing about episode 4 is so much stuff happens in it.
And then you go, “Wait, wait, there’s a lot more to go.”
It’s just brutal.
I mean, I think he’s angry that Filip did this.
And so he’s prepared something to just put the screws to her.
is the maximum security prison stuff with Clarissa.That was a tricky one.
We ended up shooting it at the base of the CN tower in Toronto.
It’s hard to build and you really wanted to get the sense of a tomb.
It’s a combination of two sets.
One is the old Toronto stock exchange, the entry point.
So the upstairs has got this kind of nice deco sort of a look to it.
And the overhead shot that you go there is a hydro plant outside of Toronto.
It was pretty cool.
And I think it’s one of the reasons we did so much more location work this season.
It really felt like it opened up the scope of the show in a great way.