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From the Writers: A Behind the Scenes Guide

Discovery writers Erika Lippoldt and Bo Yeon Kim take you behind the scenes of "The Sound of Thunder" with photos and commentary

Behind the Scenes "The Sound of Thunder"

We knew from the very outset of Season 2 of Discovery that we would write the episode where Saru would be returning to his homeworld. That meant filling in a lot of worldbuilding details both for his character’s backstory, and for the Kelpiens as a new alien species. Luckily, we were able to use both the Short Trek “The Brightest Star” and Episode 204, “An Obol for Charon” (written beautifully by Alan McElroy and Andy Colville), to set some of this up.

We wanted to build out a dynamic between the Kelpiens and the Ba’ul that was much more complex than simply prey and predator. Saru is obviously far too intelligent to just be mindless cattle. But we also wanted to find ways to portray how intelligent beings can become trapped in these situations, when a species is pre-warp not just because they are “primitive” as a culture. More than that, we wanted to create a scenario where our own, human understanding of right and wrong, of what is acceptable, is not a given. So, what if Saru’s people didn’t just accept the fact that they are prey – what if they themselves facilitated it?

We introduced this notion in “The Brightest Star.” In assuming the role of the village’s priest, Saru’s father Aradar wasn’t simply being mindlessly obedient to the Ba’ul; he represented someone whose kind have been oppressed for so long that it has become second nature to comply. He, and the rest of the Kelpiens, accepted this dynamic as “the Balance.” When Saru questioned this, Aradar admonished his son not out of ignorance, but rather wisdom. He understood that things were the way they were because it ensured a relative peace within their delicate, binary world. Aradar, in a sense, was helping his son come to terms with his own inevitable death.

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But Saru was able to break away from that vicious cycle. We often imagined Saru as the Galileo of his people. He was able to take a step back from all the ingrained beliefs his people had, in order to see things from a new perspective.

But what happens if the Galileo of your people was taken away by advanced aliens who show him a whole universe beyond what he knew… And then he returns to his home planet with his eyes fully opened to the systemic oppression that’s going on there, and the means to do something about it? This of course brings us back to one of Starfleet’s most famous rules: the Prime Directive, or General Order One. It was an exciting challenge for us to find the juiciest story to tell within these parameters…


Concept Art

The first step in making a script reality is getting designs from our production designer Tamara Deverell (based on just a few lines of description). This is concept art of the Kelpien village. Every e-mail from Tamara was a treat, as our words were transformed into beautiful worlds.

Concept Art

The Ba’ul “monolith” went through many variations, but this was one of my (Boey) personal favorites.

Concept Art

Very early concept design for a Ba’ul “culling” ship that invokes War of the Worlds. They eventually became “sentry” ships as the story changed.


This episode had a fair amount of bridge action, which meant at least one long day shooting on the bridge set. Here the cast and crew prepare to roll on the first scene of the day.

The Bridge

Because of the number of bridge crew members involved in a bridge scene, we use a three-camera setup in order to get as much coverage as possible for each take. It is always such a pleasure to work with this talented and enthusiastic group.

The Bridge

After a wardrobe change for Sonequa and Doug, the cast gathers around for a private read-through (followed by blocking) of the next scene. Script supervisor Angela is near at hand to keep an eye out for continuity issues.

The Ready Room

Our fantastic director, Doug Aarniokoski, watches Saru on the video village monitor, while in the background you can see the cast and crew actually filming the scene in the Captain’s Ready Room. Reality vs on-camera magic!

Wilson Cruz

For this scene, we wanted to track what Culber had been through in his time in the mycelial network, and get across what he’s feeling now that he’s back on the ship. Doug A set up these two shots to really get inside Culber’s head, as portrayed by the wonderful Wilson Cruz.

Saru’s Quarters

From the very early conception of the episode, we knew we wanted a scene where Siranna sees Kaminar for the first time from space.

Next, it was time to head to Kaminar, aka a beach outside Toronto. One of the many challenges of filming on location is having to contend with whatever weather Mother Nature sends our way. Naturally, this being summer in Toronto, there was a torrential downpour the morning of our first day out.

Flooded beach

Flooded tent

Not even video village was spared. But, given our limited time on location, the crew soldiered on and we got what we could until the weather cleared -- which, thankfully, it did.


A technocrane is set up on the beach so that we can capture the full scope of Saru’s home village. We don’t get to travel to alien planets as much as we’d like to on the show (mainly due to production costs), so when we do, we want to make sure we make the most of it.

Pylon on beach

Production designer Tamara Deverell and her team did an amazing job of dressing the beach to seem like an inhabited Kelpien village, including a partial pylon (pictured) and partial huts. This was of course enhanced with VFX to give it that extra alien touch!

Hannah, Doug J, Doug A

Finding the right actor to play Saru’s sister was vital to the episode — someone who can emote through her prosthetics, and do so alongside the masterful Doug Jones. We were so lucky to have found the perfect Siranna in Hannah Spear right in Toronto where we shoot.

Meeting Siranna

A lot of work also went into the garden where we first meet Siranna. Here, Doug A supervises a private blocking of the scene, which involved a lot of complex emotional turns, particularly for Hannah, who executed it beautifully.

Concept Art

Kelpien tea pot and cups were designed for the Short Trek “The Brightest Star” and for this episode.

Background Kelpiens

The background actors had to suffer through heavy prosthetics on a hot summer day on the beach, wearing those crazy Kelpien boots.

Background Kelpiens

Back indoors, we headed to the Ba’ul citadel where Saru and Siranna encounter their first Ba’ul.

Doug and Mario

Here, Doug A and props master Mario Moreira walk through the steps for the scene where Saru co-opts the Ba’ul technology in order to communicate with Discovery.

The Ba’ul

The Ba’ul presented us with a great many technical challenges, but it was amazing to witness Doug Jones and Javier Botet facing each other off in the same room.

Doug, Hannah and Doug

Doug A talks through the heartbreaking scene where Saru helps Siranna through her Vahar’ai.

Doug and Hannah

Doug J and Hannah share a brother/sister moment even in between takes. We couldn’t have asked for better Kelpiens, let alone fantastic actors and lovely human beings.

Ba’ul Alphabet

The Ba’ul language, which we imagine the Kelpiens might learn in lieu of their own written language, which was lost.

Star Trek: Discovery streams exclusively on CBS All Access in the United States and is distributed concurrently by CBS Studios International on Netflix in 188 countries and in Canada on Bell Media’s Space Channel and OTT service Crave.