Panic sweeps Mt. Thomas when an outbreak of an animal disease begins to kill humans. When Maggie suddenly collapses, PJ is desperate not to let the disease, which has already claimed two lives, take his beloved Maggie.

The words Japanese Encephalitis strike fear into the heart of PJ. It's fatal, there's no cure, and it seems to be the cause of Maggie's illness. But PJ won't give up. Now the task is to prove the doctors wrong, to find a viable alternative and breath new life into his beloved Maggie. Nick's reign as acting sergeant is rapidly turning into a nightmare as he deals with Keith Purvis and a mob of panic-stricken farmers. Having decided the spate of deaths had been caused by rabies, they slate the responsibility home to a couple of English migrants and their young daughter. Nick fulfils a promise to the girl and takes the dog into protective custody. However, the farmers follow them into town and Nick soon finds the station cut off from the outside world with a highly agitated farmer, the girl, her mother and their dog. Tom had hoped to quietly recover from his heart attack, but now finds himself standing in the heat trying to negotiate with an angry mob who have the police station under sie