A human experiment plan known as the Genesis Project abducts people from all over the universe to conduct inhumane tests on their bodies. Zaine, a young scribe working at a monastery, is abducted one day and undergoes a transplant that replaces his consciousness with that of another person's. One day, when he wakes up in the monastery hospital, Zaine is told by a nurse that he went missing for a day and appeared the next with a fever that lasted four days.

Now recovered, she asks him to deliver clean linens to a patient’s room before he can go back to his normal schedule. When he arrives, he notices that the patient --a girl-- is also down with a fever and gets kicked out by the nurses for staring at her too much. He bumps into one of the head priests, Father Gilhram, and a childhood friend, Apalo, on his way to his room and is reprimanded by the priest for being absent for four days.

That night, another childhood friend, Noa, goes to visit him in his room and tells him how worried she was when he disappeared and came back with a fever. They attend mass afterwards and Apalo tells him to meet him in the dining room. That's when he tells Zaine about a dark secret the monastery personnel are keeping away from everyone.

Zaine thinks about how preposterous the secret is even after a week has gone by. And when he goes to bed that night, Apalo sneaks into his room to wake him up so they can spy on father Gilhram in the chapter house, promising they'll get to see proof. The evidence they see further convinces Zaine that something shady is going on, and they make a break for it when they're discovered. Along the way, he bumps into the girl from a week ago and takes her with them thinking she's in danger too.

All four teens, Zaine, Apalo, Noa, and the nameless girl escape the monastery and flee into the forest. But they are betrayed, as Apalo fights Zaine to the death out of jealousy for Noa who is in love with Zaine. Apalo ends up getting crushed to death by a tree when it is hit by lightning. The remaining three then wander into a small town named Fendala after wandering the countryside. They settle in and start their new lives. Zaine gets hired by an herbalist while Noa becomes an apprentice midwife.

The more days go by, the more Zaine sees the same dream of him and another man being experimented on by a group of five people. The nameless girl, which they later find out her name is Amelia, also experiences nightmares on a recurring basis, and Zaine ends up comforting her every time, which Noa becomes jealous of. Noa makes it clear to Amelia that Zaine is hers and she should back off or else. But one day after a shower, she sees Amelia sleeping on Zaine’s bed which causes her to snap and threaten Amelia with a knife.

Zaine, oblivious to her jealousy, is dumbfounded when he sees her doing this to Amelia. Noa runs away in shame and Zaine is unsuccessful in finding her.

Later that night, Noa is remorseful for her behavior and decides to go back and apologize to both. But a pair of lawless knights find her wandering the streets at midnight and scheme a crude plan against her. Zaine goes to work the next morning and on his way sees a crowd of people outside a building. One of the spectators tells him someone was murdered there last night. He finds out it's Noa after the body is taken out and runs out of Fendala crying into a nearby forest. A traveling knight finds him there  and quickly befriends him after Zaine tells him why he was crying in the first place.

When Amelia comes up in the conversation, Zaine realizes she is all alone and dashes back to town for her. He sees that she's safe and promises to himself he will protect her from anyone, including from the people behind the Genesis Project and decides to become a knight himself.