Intro. Mario brings his daughter PJ, a medical student, to her first day of senior year at San Lazaro University. Due to his previous work as an OFW and his inability to pay his daughter's tuition, Mario has a strained relationship with PJ, who is still traumatized from failing to save her mother from a fatal stroke. She reunites with her block mates in Block Z: fellow med students and longtime friends Erika and Myles, and Block Z basketball team captain Lucas, who harbors feelings for PJ. Mario accidentally hits a pedestrian who intends to scam him, but Mario instead brings the man to the university hospital, where he meets with PJ again.
PJ and Erika are assigned to take care of Angie, a mother who appears to have a human bite in her leg. Angie suddenly has a seizure and dies shortly after, and PJ goes to comfort Angie's young daughter Ruby. Myles and fellow student Gary head over to bring Angie's body to the morgue, but Angie reanimates and bites Gary's neck, causing Myles to flee.