Bullied and ostracized, Shin Naerim is searching for an escape. She has no friends, never fights back, and simply endures the pain. Everything changes when Naerim meets Vlad Fetechou—a centuries-old vampire who unwittingly enters a blood pact with her. Their bond is that of master and servant; whenever Naerim sheds blood, a red thread appears, binding the two together. Fetechou's only wish is to become human; the only way to achieve this is to drink the blood of a witch, which Naerim happens to be. As they grow closer with each passing second, the pair learns to heal their own wounds while facing shattered friendships, strained family ties, and dreadful shadows from Fetechou's past.