“Fushigi” means mystery or miracle in Japanese, both of which have always been present on Helix but never more so than in Day 10.
The episode begins with Sarah being strapped down for a medical test now that the secret of her tumor is out. While in the machine she hallucinates a vector attack.
Meanwhile, Julia continues to reconnect with her father, Hatake. He tells her that she was taken away from him by her mother Jane because of his involvement with the kidnapping of the children. He says that most of the kids wound up with loving families, but not all. When she asks about their silver eyes he becomes more cryptic in an attempt to protect her.
In the village Anana is stitching up Balleseros again when Miksa enters. He and Balleseros insist that she and the villagers get out of Dodge before more Ilaria henchmen show up.
Julia goes to Alan to complain about how totally lame her dad is being. Alan gets caught up in the daddy issues jamboree and leaves to confront Hatake, who changes the subject by showing Alan a recording of the cryogenics scientist Doctor Adrian leaving the base with the virus sample. Alan and Julia then look at a map to find out where Adrian could be going. They realize the most likely answer is an abandoned deep space listening station, so they follow him there while Hataki plays the overprotective dad and looks on disapprovingly.
Sarah remembers the woman she euthanized and is motivated to get back to finding a cure. She meets up with Hatake in the lab and he asks her to rat on her friends because they refused to tell him where they were going. He expresses his guilt and she comforts him with the story of Edward Jenner risking a child’s life to develop the smallpox vaccine as if it were an Aesop’s Fable about utilitarianism. He later returns the favor by encouraging her to persevere and suggesting she take another look at Julia’s DNA.
Julia and Alan find Adrian at the listening station. He tries to escape but Alan throws him through a window. They tie him to a chair while Julia works on getting the radio to work and Alan looks for the backup generator.
While preparing to leave the village, Miksa tells Anana that he will go to the base alone to slow down Ilaria. Tulok alerts them that an Ilaria henchman got away on a snowmobile so Miksa chases after him.
Alan finds the generator and turns on the lights, exposing Christmas decorations as carols play. Adrian tries to get under Julia’s skin by bringing up her love triangle with Alan and Julia. She tells him to shut up and he refuses until he is shot by a sniper, who turns his attention to Alan and Julia. The radio starts working just before getting hit by a bullet.
Peter drops down from the ventilation shaft and rummages through some papers, presumably looking for something to read. He doesn’t like any of the magazines in Doctor Hatake’s office so he settles for every Helix character’s favorite literature, Hatake’s creepy Julia Walker scrapbook. He takes some of the pictures and makes his own creepy shrine in the air ducts.
Alan and Julia talk about their relationship while under fire. They find an escape door in the floor. They hear someone down there singing “The First Noel.” They find a man named Gunnar chained up with silver eyes. He says he was a scientist until Hatake locked him up for siding with Constance. He claims he is immortal and has been locked up for 29 years.
Sarah records a video about her discovery from Julia’s DNA. She says it could be the cause or just a side effect, but either way it is encouraging and may heal her tumor. She plans to get a spinal tap but has a seizure while she is working alone in the lab.
Julia starts to set Gunnar loose with bolt cutter, but he forces her to kill him instead. Just then the Ilaria flunky that was doing the sniping finds them. He ties them to chairs and asks about the virus. He threatens Julia but Miksa arrives and kills him. Alan, Julia and Miksa leave after burning the place down.
When Julia and Alan get back to the base they ask Hatake about Gunnar. He says Gunnar betrayed Julia’s mother to Constance, leading to her death so he punished him with an eternity of solitude. He also informs them that there are 500 immortals behind Ilaria. Then they are distracted when Sarah crashes. In a voiceover from her video Sarah says she isn’t afraid to die and that she will live forever through science. Hatake says Julia can save her and Julia takes a container with vials of Narvik in it out of her bag.