In the opening moments of Sweet Tooth’s very first episode, a deadly pandemic spreads and a new species of human-animal hybrids emerges. Over the course of the series, the third and concluding season of which is now streaming on Netflix, a crumbling society searches for answers, including to one very big question: Which came first, the hybrids or the virus? In the penultimate episode of Season 3, that long-standing question is definitively answered — and its consequences shape the show’s explosive finale.

Sweet Tooth viewers have watched deer-boy Gus (Christian Convery) grow from a vulnerable innocent into a leader. As Season 3 begins, he and Jepperd –– the mentor he calls “Big Man” (Nonso Anozie) –– venture to Alaska to find Gus’ mother, Birdie (Amy Seimetz), alongside Bear (Stefania LaVie Owen) and Wendy (Naledi Murray). The group of four soon, reluctantly, becomes five as Singh (Adeel Akhtar) tracks them down and tags along on the treacherous journey, despite their distrust of him.

Let’s dive into Sweet Tooth’s race to its epic conclusion.

Matt Klitscher/Netflix

Who is Helen Zhang?

Cold and cutthroat, warlord Zhang (Rosalind Chao) wants to return to a world where only humans, and not hybrids, are birthed, and she sees Gus as an integral part of her plan: She believes, based on his mother Birdie’s research, that he has the cure for the Sick in his blood. What’s more, she wants to wipe out the existing hybrids to restore humankind to its former glory.

Zhang sends her daughter, Rosie (Kelly Marie Tran), on a mission to track down Gus. Rosie brings her sons, the Wolf Boys, along for the hunt. The Wolf Boys are vicious, because their grandmother, Zhang, raised them to be.

Rosie and the Wolf Boys attack Gus and his crew before they can board the Whale Song, the ship that will carry them to Alaska. While Gus, Jepperd, and Singh escape by boat, Bear and Wendy aren’t so lucky. Wendy manages to hide, but Bear is captured.

Even as Sweet Tooth, Big Man, and Dr. Singh board the Whale Song, there’s an unshakeable sinister feeling in knowing that Zhang is still lurking, something executive producer Amanda Burrell credits to the character’s depth and Chao’s performance. “She was so inspiring,” says Burrell. “We cast her with the mind that she’s going to be our big bad in Season 3, but as a human she is very mama bear, and she brought all of that energy to this. [Zhang’s] desire to protect, her desire to control, her desire to really make a life for her kids — that is one she’s holding on to so tight, but ultimately she turns them toward a really dark place. Those layers were so fun to explore with Rosalind.”

Zhang isn’t the only one after Gus: His mother, scientist Birdie, has charged a close friend, Siana (Cara Gee), and her daughter, Nuka (Ayazhan Dalabayeva), with locating him. When Gus picks up a radio signal on the Whale Song, it’s Siana, who informs him that finally, after enduring many hardships in tracking down his mother, he’s only a couple days away from Alaska.

Upon arriving in Alaska, Gus, Jepperd, and Singh meet at Siana’s outpost, but Zhang and her army are hard on their heels. Zhang threatens to unleash the Wolf Boys on the outpost if Gus isn’t handed over to her, but things don’t get that far: Singh gives up Gus’ location in exchange for getting to tag along to a mysterious cave that seems to hold the answers each character seeks.

What’s in the cave?

Singh has read Dr. James Thacker’s (Joel Tobeck) journal, which contains a drawing of the cave. The clear implication is that the cave somehow harbors the origins of the hybrids and the Sick. Thacker’s sketch also depicts a dead deer, accompanied by a caption: “All was unlocked when I sacrificed the deer.” Singh decides to perform another sacrifice — of Gus — to reverse the process, under the assumption that Gus’ blood will heal the tree inside the cave and rid the world of the Sick. Zhang has other ideas: She doesn’t just want to sacrifice Gus to bring back human births, she also intends to use the tree’s sap to create a virus that will wipe out all hybrids. 

What caused the Sick and hybrids?

A tree did. While the cave is often mentioned throughout the series, the tree inside of it holds the power. Visually imposing, with antlers for branches and the Blood of the Earth surging inside of it, the tree is the origin of the hybrids and the Sick. Years back, when Thacker struck the tree with his ax, it released the Sick to kill off humans and created a new species to inherit Earth: the hybrids.

After Singh’s betrayal, Zhang’s army enters the cave. Jepperd tries to fight them off, but he’s overpowered, along with Gus and Birdie. Singh brandishes a knife, intending to kill Gus, but Birdie steps in front of her son and absorbs the fatal blow. 

As Gus mourns the mother with whom he’s only just been reunited, and as Zhang invokes the memory of his own dead wife, Singh has a change of heart and turns his knife on Zhang’s army. He’s appalled by Zhang’s malevolence, and he’s not the only one: When Zhang pulls the ax from the tree with intent to do harm, sap gushes out, and every human in the vicinity immediately falls to the ground, pinkies twitching, ill with the Sick.

To stop the tree from destroying everyone in the cave, Gus uses a flare to set it ablaze. As the tree burns (and ultimately dies), the humans are healed, but the cave begins to collapse. As shards of the cave rain down, Singh throws himself between Gus and a falling rock; crushed beneath its weight, he finds a measure of redemption at the thought of saving Gus and finding his “purpose.” With the tree destroyed, it’s up to nature to decide who will be born moving forward, humans or hybrids. Though Zhang still calls for violence, her own army is disinterested, no longer following her orders. As the survivors exit the cave, Zhang lingers behind, seemingly in a state of delirium. It’s unclear what happens to her, but one clue comes when her own pregnant daughter, Ginger (Louise Jiang), gives birth … to a hybrid. In voice-over, the Narrator (James Brolin) reveals that, “It became clear in the days that followed, that those humans would be the last. Hybrids would indeed inherit the Earth.”

Who is the Narrator?

In the struggle in the cave, Jepperd had been stabbed by Zhang and gravely wounded. After his escape, he rests against a rock, his breathing labored, and asks Gus to tell him a story. Sweet Tooth obliges, telling a tale of hybrids building a village and forming a new community. As the story unfolds, the action shifts to the future, and Gus’ voice is replaced by that of the Narrator — who is revealed to be an older version of Gus, speaking to his grandkids around a campfire, a gray-haired Wendy (Banke Moss) at his side, looking at him lovingly. The story has come true.

So, it’s been this aged, future Gus narrating throughout three seasons. As he sums up the conclusion of the series, he makes it clear that it’s the origin story for a new generation of hybrids. “All stories end, but ours has just begun.”

Showrunner Jim Mickle has been building to the old man Gus reveal since the show was conceived. “The comic book doesn’t have narration throughout. It’s really only in the final issue where you hear the story from old man Gus,” Mickle tells Tudum. “When I started on the pilot, it was an effort to connect the dots to that, but also to create a little bit of that storybook flavor. And that became the concept of the show, which is really what we are watching in these three seasons — [it’s] actually old man Gus telling the entire story of the end of humanity to the next generation.”

Having this ending in mind affected how they approached the Narrator’s dialogue. “It often meant that as we got into some of those voice-overs, it had to have been things that [Gus] would’ve known,” says Mickle. “Even though no one [was] going to call us out because they [didn’t] actually know it. It’s a little bit of a sixth sense thing. It made it tricky to manage that as we went. But we always knew that would be James Brolin. And it was always a bit of a pipe dream of, ‘If we get that third season and we get to the end, we’ll fly James down to Auckland and get him in the ears and the antlers.’ ”

So, what happens to Zhang?

When we last see Zhang, she’s left behind in snowy conditions. Mickle believes that at that point, Helen’s best days are behind her. “I think she’s done for. Her whole thing is she doesn’t want to go extinct, and she doesn’t want to be irrelevant, and she wants to have this legacy,” he says. “To leave her abandoned by her family out in the middle of the Alaskan wilderness — with no way back to civilization — is kind of the perfect way to leave her.”

What happens to Jepperd?

As the series concludes, an older Gus reflects on Big Man, saying, “His name was Tommy Jepperd. And he lives on in our stories.”

We flash back to the present day. Jepperd still leans against the rock. Gus has finished telling him the story, but Jepperd still has a question about how it ends. He asks Gus, “What about the Big Man? Did he make it back with him?”

While Gus doesn’t explicitly answer yes or no, the finale cuts to young Gus seated outside a cabin in Yellowstone, as hybrids work, chat, and laugh in the distance. Jepperd emerges with two bottles of maple syrup, handing one to Gus as they share a smile, each taking a sip and watching over the world they’re making together.

If you found yourself asking whether or not the moment between Gus and Jepperd was actually happening, it’s “a good question,” according to Mickle, who says his opinion on Big Man’s fate has changed multiple times. “I leave it up to you.” Anozie echoes Mickle’s sentiment. “I honestly do feel like it’s up to you,” he says. “I feel like what you are seeing is the story that Sweet Tooth is telling, and it might not necessarily be what happened. I think Sweet Tooth would’ve liked him to make it back.”

Convery, however, has a more definitive interpretation. “I personally don’t think he does,” says Convery. “As Gus is telling the story, I’ve seen some signs that [Jepperd] doesn’t make it. But then again, it can go either way, with anyone.”

However you interpret Sweet Tooth’s final moments, know that the series concludes exactly how Mickle imagined it would in his original pitch document from 2017. “There was literally a page in there that said how it ends, and I had kind of forgotten about that. I always knew that was there, but when I went back I was just shocked by how much it actually stuck to what it was.”

See Behind the Scenes as Gus’ Story Comes to a Close in Sweet Tooth Season 3