SPOILER ALERT: Read on only if you have already watched Sundays season 9 finale ofThe Walking Dead.

So how did they do it?

Bundle up and read on!

TWD_916_GP_1113_0264_RT

Gene Page/AMC

(Also check out showrunnerAngela Kang answering our season finale burning questions.)

I was just looking for some light flurries or something.

Instead, we got a massive blizzard.

TWD_916_GP_1113_0240_RT

Gene Page/AMC

Ive been dying for frozen zombies too.

Some of the greatest moments in the comic books involve frozen zombies.

And its something weve been talking about and wanting to do for a long time.

- The Walking Dead _ Season 9, Episode 16 - Photo Credit: Gene Page/AMC

Gene Page/AMC

So we started prepping, and following up on episode 15 is a big deal.

That episode in itself felt like a finale, because of just the emotion and everything that happened.

And this wasnt just a first for the show.

Im like, Ah, this is going to be great!

Ive never shot in fake snow before.

Ive never done anything like this.

And it wasnt just snow, theres a blizzard.

They assume theyre being followed.

And it was probably the biggest undertaking thatThe Walking Deadhas ever done in terms of a production design scenario.

There were so many different hurdles you guys had to clear to make this happen.

Thats such a great classic, provocative horror moment.

Otherwise, they look stupid.

They also have 60 people with them.

Theyve got to get those people across the river safely and protect themselves, all at the same time.

So, it kind of all falls at different rates and then it glistens.

I really wanted that moment.

Its also a great little F.U.

And then theres the zombie thats frozen into the water, that Lydia encounters.

And then poured paraffin wax on it, to make it look like frozen ice.

So it looked like an infinity pool.

But I was super proud of how all that stuff looked.

It was a challenge for sure.

So we created this little wedge, and I felt like we missed that moment.

That moment of them playing in the snow.

And run over here and start making snow angels, and playing in the snow.

I just gave her something and she was like, No, its great, I love it.

And she put it all in.

I just wanted the episode to end their journey to end on a high note, a sweet note.

When I look at it, I see Norman throwing snowballs.

But we caught a really nice moment.

The last day of shooting it was probably the coldest day.

And it was all this different stuff, but the minute it rains, your snow is dead.

Are you sad to say goodbye to the Kingdom?Hell no!

[Laughs]I love shooting up there.

I introduced the Kingdom when it first popped up a couple of seasons ago.

When the show works is when its nomadic.

He kept saying, Cmon!

Theres all these buildings here.

Why cant they just fix the buildings?

They rebuilt all of Alexandria, why cant they rebuild the Kingdom?

I had a couple ofEvil DeadEaster eggs this season.

We had the Necronomican in episode 5.

The cabin that Rick goes into was designed after the cabin fromEvil Dead.

That was a tribute toReturn of the Living Deadand the half corpse on the table.

Also check outWalking DeadshowrunnerAngela Kang answering our season finale burning questions.

And for moreTWDscoop, follow Dalton on Twitter@DaltonRoss.