Vitaliy Kravits is a child of Chernobyl, born with a rare health condition after the nuclear disaster. Separated from his twin brother, he is adopted by a British couple and receives a chance for a new life in the UK.
 
Thirty years later, Vitaliy is an extreme sports influencer who spends his time in urban exploration and travel. While snowboarding in Scotland, he meets is invited to the house of an eccentric German couple. There, he is drawn to a Cold War-era dossier, written in Russian, which reveals a mysterious object, the Seeds of Sky. 
 
In the search, he stumbles across a classified underwater facility hidden in Montenegro and learns that his twin brother, a prominent scientist, has died in Berlin of a reported heart attack. Police officer Leah Belstein believes the case is more complicated, and as their paths intertwine, the origins of the Seeds of Sky are revealed.