An illegal biological weapon K-55 is stolen from a university lab. They can't even call the police because of the secret nature of the weapon. The school lab then receives a message stating that the entire country is now being held hostage and they must pay a ransom of 300 million yen. Kazuyuki Kuribayashi, who works as a senior researcher at the university lab, is selected for the mission to take back the stolen biological weapon. Meanwhile, he agonizes over his difficult relationship with his adolescent son. ~~ Adapted from a novel by Higashino Keigo.