The Silent Sea Ending, Explained

In recent years, the South Korean entertainment industry has been going from strength to strength. After ‘Kingdom,’ ‘Parasite, ‘Squid Game,’ and ‘Dr. Brain,’ comes the space horror ‘The Silent Sea.’ The series relies on atmospheric terror, lingering for a few extra moments on certain scenes to build the tension. Set in a dystopic future, the story follows a group of astronauts as they travel to a lunar station to retrieve something referred to only as the “Sample.” Upon their arrival, they soon find several discrepancies in the story they have been told about the facility. But then, they realize that their mission might hold the key to human salvation. Here is everything you need to know about the ending of ‘The Silent Sea.’ SPOILERS AHEAD.

The Silent Sea Recap

The story takes place on an Earth where rivers have dried out, and the average annual rainfall remains perpetually and dangerously low. The oceans are also rapidly drying out. According to an organization called the World Water Resource Council, the world’s water will be decreased by 40% in the next decade. Infant mortality has reached a record high. Most of the deaths are the result of drinking contaminated water. Various governments around the world, as well as private companies have heavily invested in vertical farms that can curtail water usage.

As water has become the most sought-after commodity, institutional discrimination has inevitably emerged in the government’s handling of it. Legislation for equality in water distribution has been rejected multiple times. Elites of the society carry a gold card that gives them unlimited access to water. The astronauts heading towards Balhae have been promised such accesses upon completing their mission.

Five years after 117 crew members died at the Balhae Lunar Research Station apparently due to a radiation leak, the South Korean Space and Aeronautics Administration (SAA) puts together a team to travel up to Balhae and retrieve the “Sample,” a mysterious substance that is always kept in a capsule designed to maintain very low temperature. Choi, the director of the SSA, and Mr. Kim (Heo Sung-tae) claim that they don’t have much information about the substance themselves.

Among the new crew, Dr. Song Ji-an (Bae Doona) is a renowned astrobiologist turned ethologist. Although Captain Han Yoon-jae (Gong Yoo) is in charge of the mission, Director Choi tells the crew that Dr. Song will be the final authority on the Sample. However, none of the crew members except Han know that Dr. Song’s sister was the head of research at Balhae before the tragedy. Before her death, Dr. Song’s sister called her on the phone. Angry about her sister leaving her alone on Earth, Dr. Song didn’t pick up the phone. It’s a decision that she has come to regret deeply. She also received a message from her sister, asking her to find Luna.

After they arrive at Balhae, they start to notice odd things. They find the bodies of all the crew members as well as of a mercenary. However, the cause of death is not radiation leak as they were told, but drowning. As the crew tries to find the Sample, they don’t yet realize that they have traitors among them. These operatives have been sent to Balhae to acquire the Sample and eliminate the rest of the crew after they are successful.

In the season finale, the truth about Balhae and Dr. Song’s sister is revealed. The crew is further depleted as more members die. Dr. Song finds out why Director Choi insisted for her to be part of the mission.

The Silent Sea Ending: What Is the Sample? What Is the Lunar Water? What Happened at the Balhae Station?

The Sample and the lunar water are one and the same. The lunar water is what its name suggests — water from the moon. However, it has certain unique properties that differentiate it from ordinary water. When the lunar water comes into contact with an organic substance, such as blood, it starts to expand rapidly. Under the leadership of Dr. Song’s sister, the scientists at Balhae were researching how to make lunar water safe for consumption. Because in its natural state, if even a molecule of the substance ends up inside a person, they die by drowning from within.

Dr. Song’s sister and her colleagues studied cell fusion and genetic combinations for developing methods to help humans survive lunar water. They used cloning to create test subjects for their research. Ultimately, Director Choi and the rest of the government decided to close Balhae because they were afraid that the news of their atrocious experiments would reach the public. The military was sent to ensure that no crew member left the facility after exposure to lunar water. Director Choi later sends Dr. Song to Balhae because she thinks that the latter will never reveal her sister’s horrible secrets.

Who Is Luna in The Silent Sea?

Dr. Song first encounters Luna when the latter tries to retrieve lunar water from Gisu and ends up killing him in the process. She and the crew initially think it’s some kind of a creature because of its inhuman speed and power before discovering how she looks like. Luna is the 73rd clone used in the experiment mentioned above. She is the only clone who survives the test, effectively making her the one on whom the fate of humanity is hinging.

Luna not only can tolerate the water, she even gains certain abilities because of it. The lunar water heals her injuries exponentially faster and has apparently given her the power to walk outside in the lunar atmosphere without needing a suit or breathing apparatus.

Who Are the Traitors in The Silent Sea? Who Are They Working For?

As revealed in the course of the series, both Gisu and Taesuk are traitors. Although the show never explicitly mentions it, it is heavily hinted that they both work for a transnational corporation called the Resource Exploration for Space Mining and Planetary Development, or RX, for short. According to one of the members of Captain Han’s crew, almost all the nations of the world have problems with RX. They have garnered such notoriety that they have come to be known as the resource mafia.

Does Captain Han Die in The Silent Sea?

Yes, Captain Han dies in ‘The Silent Sea.’ As Balhae starts to flood with lunar water, Captain Han gets error messages from the sensors within the chamber where he, the remaining crew, and Luna are hiding. He realizes what he must do and steps out. He locks the door behind him and initiates airlock depressurization, and the sensors start to work inside the chambers. He is later thrown out into the lunar atmosphere by the water pressure.

In his last few moments, Luna approaches him and tries to give him his badge back, on which his daughter placed a sticker. But Captain Han dies before he can take it. Before his departure, he promised his daughter that he would return. Although he isn’t able to do so, his actions just might have ensured that his daughter will have a long and healthy life.

Who Rescues Dr. Song, Luna, and Dr. Hong?

After Dr. Song, Luna, and Dr. Hong escape from the Balhae Station before it’s flooded, they are picked up by a space shuttle. Now, we know that two shuttles were heading toward the moon. If Mr. Kim sent one, the other was probably sent by the    RX. The South Korean government most probably destroyed the RX shuttle, and it was Mr. Kim’s shuttle that Luna and the others board. Mr. Kim and several other individuals at the SAA believe that Luna and lunar water belong to the entire humanity and not just to a particular country or corporation, and they have most likely ensured that things would pan out that way.

Read More: Where Is The Silent Sea Filmed?