‘The Silent Sea’ Ending, Explained – Did Song Rescue Luna 073 From Balhae Station?


When Galileo invented his telescope and looked at the Moon, he saw dark spots on its surface, which he believed to be water. He referred to them as “The Silent Sea.” In 1651, astronomers Giovanni Battista Riccioli and Giovanni Battista Riccioli renamed it “Mare Tranquillitatis” (or Sea of Tranquility). Well, there is always some reality hidden in the fiction, I guess. Based on the belief of these astronomers, several lunar missions were carried out to find traces of water on the Moon. And that’s what Netflix’s South Korean series, “The Silent Sea,” is about. Space explorers hope to find water to save the human race from extinction.

Director Choi Hang-yong has adapted The Silent Sea series from his own short film that was released in 2014. The narrative brings a group of space explorers on a 24-hour lunar mission. They have to retrieve lunar water samples from a closed South Korean facility on the Moon called the Balhae Lunar Research Station. But as the team enters the facility, a plethora of secrets start to unravel, which further complicates the mission. So let’s dig deep.

‘The Silent Sea’ Plot Summary

In a dystopian future, the rivers in major cities worldwide dry up due to less or no rainfall. The countries are experiencing declining sea levels and an increase in infant mortality. Due to a water shortage, the South Korean government started rationing water to all its counterparts based on their ranks. Officials with a higher “water grade” receive more water, which enrages ordinary citizens who demand equitable water distribution.

Amid such chaos, Kim Jae-sun (Heo Sung-tae), an official of the Space and Aeronautics Administration (SAA), visits Doctor Song Ji-an (Bae Doona), an astrobiologist who works at HSRC. Doctor Song’s elder sister, Song Wonkyung, used to work for SAA and lost her life five years ago in Balhae Station after the spread of radiation inside the facility. Director Choi of SAA offers a vital mission to Dr. Song in which she is required to go to Balhae Station. In the hope of finding the answers to her older sister’s death, Dr Song undertakes the mission.

At the SAA facility, Dr. Song meets the captain of Balhae Lunar Mission, Han Yoon-jae (Gong Yoo), and other team members. Director Choi briefs the team that they need to retrieve an essential sample from closed Balhae Station in 24 hours before the government can shut it down permanently. When Dr. Song requests more detailed information on the “sample,” Director Choi and Kim refuse to share further details. Dr. Song feels something is amiss with the whole ordeal, yet to find her sister’s remains, she boards the space shuttle along with the space explorers.

Dr Song and Captain Han inside Balhae Station
Credits: Netflix

What Happened At Balhae Station 5 Years Ago?

Due to prolonged drought conditions, many developed countries began hunting for extraterrestrial resources on the Moon. However, when they failed to find any signs of water, they pulled out their scientists, but South Korea didn’t give up. One of their chief scientists, Song Wonkyung (Song Ji-an’s sister), found traces of “Lunar Water” on the Moon.

Director Choi and SAA believed that lunar water would give them an advantage over other developed countries. Thus, they secretly started experimenting with lunar water at Balhae Lunar Station. However, the molecular structure of lunar water differed from that of Earth’s water. Dr. Song explained that it contained some kind of extraterrestrial virus. When the Lunar Water came into contact with a living host, it started multiplying inside the host’s body until the host was alive. Because of uncontrolled multiplication, the lunar water killed its host.

Five years ago, lunar water accidentally got leaked inside the Balhae Station. The authorities had to permanently close the station. They lied to the world that they locked their scientists inside the facility because of a radiation leak. SAA didn’t want their secrets (inhumane experimentation) and discoveries (Lunar Water and Lunar 073) to get exposed to the world.

Lieutenant Ryoo Tae-seok, who came with Captain Han on the mission and worked for RX (Resource Exploration Mafia), was the one who shut down Song Wonkyung and other scientists inside the Balhae Station. The whole incident left a mental scar on Ryoo, who felt that he could have evacuated these innocent souls but had to leave them to die because of his government. Hence, he changed his position from pilot to engineer because space travel reminded him of the manslaughter he was a part of. He only undertook the mission to steal Lunar Water for RX.

What was Lunar Water?

Dr. Song’s sister, Song Wonkyung, discovered water on the Moon, which he called “Lunar Water.” However, after the permanent shutdown of the Balhae Station, the years of research and discoveries got lost. Director Choi and SAA wanted the space explorers to bring samples of lunar water back to Earth to continue with their research. They wanted to control the way it multiplied to commercialize it and save mankind.

Doc Hong and Dr. Song believed that lunar water multiplied inside a host’s body. It drowned their internal organs, leading to fatal death. It also affected the host mentally, as the host often saw starfish around them and felt drowning in the sea, which suffocated their will to live.

Though Lunar Water was highly contagious, it could be made less effective if stored below 80 degrees Celsius. That was why the lunar water never left the Moon’s surface because the low temperature froze its molecules. Though normal humans failed to sustain the effects of lunar water, there was one genetically modified clone on Balhae Station who received superhuman abilities from it. Before her death, Song Wonkyung sent Dr. Song an encrypted message five years ago. Wonkyung wanted Ji-an to find her life’s most extraordinary invention, so the message was coded as “Find Luna.”

Who was Luna 073?

When Captain Han’s crew tried to retrieve the sample, they were attacked by a ferocious intruder named Luna. At some point, Dr. Song figured out that Luna was a teenage girl who was wearing a lab coat with Song Wonkyung’s name tag on it. She believed that the mystery surrounding Luna was somehow connected to her sister.

The SAA wanted to find ways to make lunar water safe for humans, and hence they forced the Balhae scientists to start human trials. The head scientist, Song Wonkyung, didn’t want to harm innocent souls. Thus, with the help of cell fusion and genetic recombination, Song Wonkyung made clones called Luna and started experimenting on them. Initially, the team only met with failure, which led to the death of 72 Luna Clones, until finally, the 73rd clone survived the effects of Luna Water.

Song Wonkyung with Director Choi of SAA
Credits: Netflix

During her research, Song Wonkyung discovered that fish could survive the Moon’s water. Thus she genetically combined the DNA of a fish and a human to create Luna 073. Probably because of this reason, Luna 073 had gills on her cheeks. The Lunar Water also gave special abilities to Luna 073. She had incredible healing capabilities and was able to move swiftly.

It could be speculated that Song Wonkyung didn’t tell Director Choi about the survival of Luna 073. She never asked the crew to bring Luna and demanded only Luna Water. Song Wonkyung wanted to protect Luna from SAA and thus sent an encrypted message to Dr. Song to find Luna. In Luna 073, Dr. Song saw a glimpse of her sister and therefore decided to save her at all cost.

How Did Balhae Station Get Flooded With Water?

After a leak of Lunar Water in Balhae Station five years ago, the water accelerated the growth of a seed inside a storage unit. As the water came into contact with living scientists locked inside the facility, it multiplied uncontrollably, leading to a flood. It could be speculated that the seed absorbed the floodwater, which led to the bushy growth of plants inside a remote unit inside the main lab data storage chamber. In The Silent Sea Episode 5, Luna 073, attacked an astronaut whose blood was contaminated with Lunar Water. The human blood, as well as the plants, caused another flood in the secret storage unit.

Lieutenant Ryoo Tae-seok, working for RX, betrayed his own crew and stole the Lunar Water samples. He closed all the gates to trap Captain Han and the other crew members. When the astronauts tried to escape through the air ventilation shaft, Ryoo activated the air purification system. When the system tried to clear the secret storage unit flooded with water, it carried water into the ventilation shaft. As the water was thrust out of the facility, the low temperature on the Moon’s surface froze the water near the discharge units. When the water failed to leave the facility, it pressured the ventilation shaft and started leaking from the pipes. The lunar water flooded the entire facility in no time, and the surviving crew members had to run for their lives.

Lunar Water absorbed by a seed
Credits: Netflix

‘The Silent Sea’ Ending Explained

During a chase sequence, Luna 073 bit Dr. Song’s hand and, in turn, transferred her immunity to her. It was the only reason why she survived the deadly Lunar Water contact in the end.

Dr. Song believed that Lunar Water and Luna could save the human race. She believed that it belonged to the whole of humanity and not just one country. Hence, with the help of Mr. Kim’s rescue spacecraft, she decided to take Luna to IISB (The International Institute of Space Biology). Dr. Song wanted to take Luna to neutral territory where she could live a normal life like any other teenage girl.

Lieutenant Ryoo Tae-seok was waiting for the RX space shuttle near Gate 7, so Captain Han decided to leave the Balhae Station from the same exit. At the end of The Silent Sea, Ryoo transformed into a salient protagonist who believed that humans didn’t deserve Lunar Water. He blamed himself and SAA for the manslaughter of Balhae Station scientists five years ago. However, to save his crew, Officer Gong sacrificed his own life to kill Ryoo.

As the remaining survivors, Captain Han, Doc Hong, Luna, and Dr. Song, reached gate number 7, Han figured out that the gate had to be manually opened. He sacrificed his life so that the last hope for humanity could survive. But Han not only offered his own life, but also the chances of his daughter’s survival, who needed a water upgrade to live. She was the sole reason why he undertook the mission.

Luna 073 survived in the end of Silent Sea Series
Credits: Netflix

As the gates opened, Luna left behind her astronaut suit and disappeared. For a moment, Dr. Song believed that Luna would die due to a lack of oxygen. But probably because of her genetic modification or Lunar Water abilities, Luna roamed freely in the oxygen-less space.

Dr. Song tried to find Luna, when she saw Captain Han and Luna on the moon’s surface. Either Captain Han’s body was thrown out of the station due to the water pressure or he was rescued by Luna who used her special abilities to save Captain Han. Before his space suit powered off, Han saw Luna standing in front of him as she reminded him of his daughter.

At the end of The Silent Sea, a rescue space shuttle arrived on the Moon to take Doc Hong, Luna, and Dr. Song back to Earth. The survivors boarded the shuttle safely, and the lunar water samples were secured. Maybe, Han boarded the rescue shuttle as well and survived, because his fate wasn’t revealed in the end.

Dr. Song would probably invent an antidote to make lunar water safe for humans. Lunar water had an incredible capacity to multiply, and thus, after this life-changing invention, Planet Earth would never have to face water scarcity again. Maybe it was the happy ending, but if not, Season 2 will bring new conflicts and challenges.

The Silent Sea is a 2021 South Korean Space Science Fiction Series directed by Choi Hang-yong. It is based on his short film, The Sea of Tranquility.

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Shikhar Agrawal
Shikhar Agrawal
I am an Onstage Dramatist and a Screenwriter. I have been working in the Indian Film Industry for the past 12 years, writing dialogues for various films and television shows.

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