Beyond the deep snowfields of northern Russia lies Nukvaken, a research institute existing in complete isolation from the outside world. Officially, it was an institution for research in rare diseases, neurology, and psychiatry, but not all the research conducted within was ever disclosed to the public.

Guest was one of the most prominent young researchers at Nukvaken. As the Principal Investigator (PI) of a project to treat rare diseases causing abnormalities in emotional perception and regulation, she determined the direction of research and oversaw the clinical processes and the entire research team.

The key clinical subject she was in charge of was Alexei Sokolov's grandfather.

Abandoned by his parents, Alexei was raised by his grandfather since childhood. Thanks to the Sokolov family's immense wealth, he grew up wanting for nothing, but the person most special to Alexei was always the grandfather who took him in. He deeply respected his grandfather and loved him as his only family.

However, he did not know the true nature of the illness his grandfather suffered from.

Alexei simply thought the old man, who regularly visited the hospital, had become a bit frail. Even on the day he personally drove his grandfather to Nukvaken, he did not realize that it was not a hospital.

And on that day, Guest discovered the hidden side of the research.

She found that one of the senior project managers was preparing a drug that was not part of the official treatment protocol. It was not a drug meant to treat the disease. It was a type of behavioral suppressant designed to inhibit the patient's emotional responses and dull their motivation and judgment, making it much easier for the research team to control the patient.

Guest refused the administration.

The purpose of the research was to treat the patient, not to turn them into something easy to handle.

However, the senior researcher ignored her objection, citing research results and the institution's interests. Guest raised objections several times, and the conflict between the two eventually escalated into a public confrontation.

Then came the grandfather's next visit.

Guest was forcibly isolated in a laboratory in the research wing. She even injured her ankle while resisting. While she struggled to release the lock with bloodied hands, preparations for the drug administration were underway on the other side of the building.

At that moment, Alexei, who was wandering inside the research wing, discovered the locked laboratory.

He had stumbled upon it while trying to find where his grandfather had disappeared to. Alexei found Guest collapsed behind the door and, without much hesitation, bypassed the lock to let her out.

Guest could barely support herself on her injured ankle, but she headed straight for where the grandfather was.

But it was already getting late.

The drug was scheduled to be administered soon.

There was no way to steal or discard the medicine. Above all, the side effects the drug might leave on a patient had not even been fully verified.

Guest hesitated for a moment.

Then she snatched the drug and took it into her own hands.

She decided it was better for her to bear the burden than to let someone else be injected with it.

Without knowing that this choice would completely change her life.

Not long after, Alexei's grandfather's condition deteriorated rapidly, and he eventually passed away.

Even after the funeral, Alexei could not shake off a strange sense of unease. The records of his grandfather's treatment process were far too incomplete, and no one could give a clear explanation of the place he had last visited.

Eventually, Alexei headed back to Nukvaken.

And there, he found the woman he had rescued once again.

Guest was no longer the person she used to be.

With her emotions and willpower significantly dulled by the drug, she was effectively abandoned in a corner of the research wing. She was held responsible for ruining the research and received no protection because she had defied the senior researcher's orders.

Alexei could not leave Guest behind and go back.

Both to find out what his grandfather, who raised him, went through until the end, and to find out why the woman who saved him was abandoned in such a place.

That day, Alexei took Guest out of Nukvaken.

And he took her to his house.

A man who lost his grandfather and a woman who lost her emotions.

Becoming each other's only remaining clue, they began to uncover the truth of Nukvaken.