While Rachael is swimming in a river she feels excruciating pain. By the time her brother drags her to the river bank, she is unconscious and in cardiac arrest. The venomous tentacles of a box jellyfish are still wrapped around her legs, continuing to pump toxins into her body. Then, football player Peter has a high pain threshold, as a red-bellied black snake bites him on the foot. Finally, Megan suffers from nausea and vomiting from a redback spider bite. Is it too late to save her life?