The ending of Netflix's "All of Us Are Dead" leaves the door open for a second season of the zombie thriller. Here's a breakdown of exactly what happens.

• Netflix's "All of Us Are Dead" follows a group of Korean high school students in a zombie outbreak.
• The first season's revelatory final moments leave the door open for a second season of the show.

"All of Us Are Dead," a Korean zombie thriller directed by Lee Jae-kyu and Kim Nam-su, hit Netflix on January 28. In that time, the series, which is based on the popular Webtoon comic "Now at Our School" by Joo Dong-geun, has become one of the most popular on Netflix globally.

The series, which reached number one in Netflix's top ten titles a week after its release, follows a group of teens who have to fight their way out of their high school, which becomes the epicenter of a zombie outbreak in the fictional Korean city of Hyosan. As the virus, created by a scientist who is a teacher at the school, spreads throughout the town, the situation becomes more and more dire as the government's resources — and rescue bandwidth — stretch further and further.

While the show isn't yet confirmed for a second season, it leaves the door open for further possibilities and ramifications of the Hyosan epidemic. Here's a run down of everything that happened in the ending of "All Of Us Are Dead," and what questions still remain.

Warning: Major spoilers for the entirety of "All of Us Are Dead" season one are ahead.

On-jo doesn't find Cheong-san when she returns to the school to look for him

After almost a full season of build-up, On-jo accepted Cheong-san's name tag in the season's penultimate episode 11, a gesture the show establishes as meaning one student wants to be in a relationship with another, kissing him after Gwi-nam bit him.

His fate likely sealed by the bite, Cheong-san sacrifices himself in the finale to lure the zombies away from his friends in the construction building. Gwi-nam finally catches up to him, succeeding in gouging out his eye the same way Cheong-san had gouged out his earlier in the season, but the pair are later caught in the explosion.

On-jo returns to the school with Su-hyeok and Nam-ra, but they don't find Cheong-san. Nam-ra, with her heightened half-zombie (or "hambie") senses, tells On-jo that she doesn't smell anyone in the building.

Soldiers sweep Hyosan, killing any zombies that weren't caught in the bombings

Following the four bombings, the military sweeps through the city, killing any straggling zombies and marking certain zones safe or restricted. There's a brief shot of Cheong-san's mother's restaurant, Cheong-san Chicken, which is marked as a safe zone.

On-jo, Su-hyeok, Dae-su, Mi-jin, Ha-ri, and Hyo-ryeong make it to the quarantine facility

Following the bombings, the group of teen survivors makes their way through the city. Things seem safe until Nam-ra hears a group of zombies coming for them. In the ensuing battle, Wu-jin gets bitten, leading Nam-ra to have to snap his neck so he doesn't attack anyone else. Later, unable to control her urges, Nam-ra attacks On-jo, but stops herself from biting her and runs away.

Only six students — On-jo, Su-hyeok, Dae-su, Mi-jin, Ha-ri, and Hyo-ryeong — make it to the military barricade, where they're escorted to safety in the quarantine facility.

Over half of the original group of students died along the way, including I-sak, Gyeong-su, Ji-min, Na-yeon, Joon-seong, Min-jae, and (apparently) Cheong-san.

The surviving residents of Hyosan remain in quarantine, even months after the crisis

A flashforward in the finale shows that three months and 17 days after martial law was declared in Hyosan, the National Security Council lifts it. However, residents of Hyosan remain in quarantine given that the incubation period of the Jonas virus, which causes people to turn into zombies, still remains unknown. Donations from other parts of the country flood into Hyosan, where residents are kept contained and are subject to curfews.

There's also a National Assembly hearing set to take place regarding the bombing of Hyosan, but news reports in the show say that party leaders agreed to indefinitely postpone it until the epidemic was resolved. This follows military commander Jin Seon-moo taking full accountability for the situation on video, and later dying by suicide in the wake of the bombing.

On-jo tends to a memorial for her dead friends outside of the quarantine area

On-jo ventures outside of the quarantine facility on what seems to be a regular basis, leaving snacks at a tree adorned with ribbons that hold messages for I-sak, Cheong-san, and Nam-ra.

The note for Cheong-san reads, "Cheong-san, I love you." On-jo still carries his name tag with her.

Nam-ra is living with another group of half-zombie 'hambies' in Hyosan, outside of the quarantine facility

Months later, while tending to the memorial for Cheong-san and the other dead students, On-jo sees a campfire that she suspects was lit on the roof of their high school by Nam-ra. She, along with the rest of the surviving group, trek out to the school.

There, they find Nam-ra, who tells them that she missed them and that she's found other "hambies" like her — people who aren't quite human, and not quite zombie. She refuses when On-jo invites her to return with them, but tells her that they're still friends even if they're apart. She tells her friends that her group has arrived, and then leaps off the roof of the school to presumably join them.

"All of Us Are Dead" doesn't fully explain the logic behind "hambies," specifically why some people like Nam-ra retain their sentience while others like Na-yeon don't, despite the fact that both of them were bitten by Gwi-nam, another hambie. The existence of more "hambies" also sets up more story for a possible second season that more fully explores the Jonas virus — notably, why it affects some people differently than others.

Lee Byeong-chan's original goal in creating the Jonas virus was to help his son convert fear to rage, and overcome his bullies. It stands to reason that those underlying themes may have something to do with who it affects.

Eun-ji and Jae-jun are both gone from their original cells in the quarantine facility

Eun-ji, the girl who was ruthlessly bullied by Gwi-nam and his crew before the zombie outbreak, was the first "hambie" to be captured by the military. While they briefly experimented on her and kept her in custody in the quarantine base, she's gone by the final episode, her containment room replaced with a table and chairs.

Eun-ji, as well as Jae-jun, the turned soldier, are presumably still in military custody, but the show doesn't reveal where they've gone by the end of the first season, or what further research is being conducted regarding the virus.

Officials find Lee Byeong-chan's son and wife, tied up in his home still

While sweeping Hyo-san, men — presumably government officials — find Lee Byeong-chan's family, still held within the home where he filmed his research vlogs. Both are still fully turned, and malnourished.

One official tells another to transport the pair carefully, saying that they cannot be lost or damaged.

While Hyeon-ju, the student bitten and infected by the mouse in Lee Byeong-chan's lab in the series' first episode, was the one who spread the Jonas virus to the entire city of Hyosan, Lee Byeong-chan's family were the first people to have been infected with the virus. In government custody, it's likely that they'll be used for experimentation, to better understand the virus.

The entire first season of "All of Us Are Dead" is available to stream now on Netflix.