The story gets more intense as "The Silent Sea" episode 5 illustrates a possible survivor at the Balhae Lunar station.
As Song Jian and Captain Ha Yun Jae tried to find the database storage, they unexpectedly saw a room full of fauna.
'The Silent Sea' Episode 5: Space Team Finds the Samples
While the group searched the area, they saw vines crawling up the walls and a room filled with plants.
However, what's interesting is that the crew found a facility that is different from any other area-it's a wall with capsules filled with lunar water samples in its prime condition.
Han Yun Jae instructed his team to retrieve the samples while Chief Gong Soo Hyuk, Kim Hee Sun and E1 secured the premises from possible attacks.
Sensing that the intruder might be in the area, Captain Han reminded everyone to keep their guards up.
READ MORE: 'The Silent Sea' Episode 4: The Elite Space Crew Learns About the Motive Behind the Expedition
Interestingly, the unidentified creature appeared in the hallway, attacking E1, who was holding a capsule. Luckily Kim Hee Sun survived the attack by firing at the intruder.
On the other hand, Song Jian noticed that one of the samples broke, causing the lunar water to multiply as it gets near E1's body.
Captain Han tells everyone to evacuate the place and return to the command station.
Here, Doc Hong operates on E2, who was also attacked by the intruder. He fractured his ribs and had to undergo an operation.
The Crew was Convinced that the Intruder was a Kid
During their discussion, they were surprised to see that the unidentified creature was a kid and pointed out that a human and not even a kid could survive life in space.
With new information, Captain Han reported everything to Space and Aeronautics Division (SAA) Director Choi, but she insists that they have to bring the samples, whatever it takes, even if it means that they have to kill the child.
He then asked if there was a possibility of survivors in the area, to which Director Choi denied and reminded him to focus on his mission.
Lieutenant Ryu Tae Suk is the Spy
"The Silent Sea" episode 5 also featured another challenge that the group might soon face.
While E2 is recovering from the surgery, Lieutenant Ryu Tae Suk contacts the RX through a special device which was also seen in Lee Gi Su's pockets.
It appears that the lieutenant is also after the lunar water and was given by the RX a go signal to kill his crew members just to get the samples.
Just when he was about to steal the sample, Song Jian and Doc Hong entered the room and saw Ryu Tae Suk transferring the samples.
Being the astrobiologist, she tells the lieutenant where the samples should be.
Song Jian Comes Face to Face with the Intruder
At the infirmary, Ryu Tae Suk, Doc Hong and Song Jian were surprised to see the intruder right on the front of the door.
The feisty lieutenant shoots her, leaving the kid injured.
As the episode ends, Song Jian tries to calm her down by giving her the capsule.
Will the intruder take it or attack the astrobiologist?
