A single mother working at C. Jacinto Hospital as a graveyard shift security guard, Mia (Julia Montes) turns night into day in order to give her son, Xavier (Prinz Skie Bautista), a fulfilling life. Her civil relationship with her ex-husband, Emerson (Joross Gamboa), turns sour when the topic of their child's custody arises. Things take a turn for the worse when a severe dengue virus befalls Xavier. Desperate to find the cure to her beloved son's condition, Mia puts her life on the line, unaware of the wicked force lurking behind the curtain.

Christina (Meryll Soriano) grows deeply alarmed when an accident at Delilah's (Denise Laurel) laboratory causes virus-carrying mosquitoes to break loose. Elsewhere, Mia (Julia Montes) finds proof that the mysterious device she found in Xavier's (Prinz Skie Bautista) room can show her the future. Because of this, Mia becomes determined to save Christina's life and change the course of her own tragic fate.