In a war-torn world: Every day, Sak suffers as he attends 'the School', a research facility studying 'possessors of the Core' - people who have obtained special abilities... And the reason for his torment is his subpar Core. But one day, a plague unlike any the world has ever seen, strikes outside 'the School' and eventually infects a person within it. Upon infection, this disease forces the infected to attack the people around them without mercy. Sak, shakes with fear as he comes face to face with the infected victim. And Ginger, the upperclassman who has always been Sak's greatest pillar of support, informs him of the existence of his 'Caller'. "If you want to live, you have to find your Caller." Being essentially forced out of the School, Sak wanders blindly and soon finds his Caller. The two begin journeying together, however...

Official Webtoon:
Ridibooks, Bomtoon, Naver Series, MrBlue, Bookcube

Official Translations:
English
Japanese: Beltoon, Lezhin, Comico, cmoa

Note:
The author announced that they're preparing the official translations for several countries.