Eva, a young virologist, who helps the local park ranger research the Tasmanian Devil Facial Tumour Disease, a contagious cancer that has wiped out nearly 90% of the population. But when her husband is bitten by a stray dog, she suspects the virus has mutated to cross species and is causing violent outbursts in the hosts. Infection soon spreads through the locals and Eva must choose between saving the man she loves or the rest of humanity.