Michael treats a nervous bride-to-be at Holt Neuro for headaches and a fainting spell, but it's her mother who exhibits symptoms of a serious condition – a possibly fatal abnormal heartbeat. When it is revealed that the condition was most likely brought on by drinking again after a decade of sobriety, her daughter storms out and Michael tries to convince the mother to get surgery before chasing after her daughter in an attempt at reconciliation.
At the clinic, a schoolteacher comes in complaining of strep-like symptoms and soon begins suffering from severe memory loss. Michael and Kate suspect meningitis, but the tests come back with a much more sobering result – rabies. As Michael attempts to save her from an almost certainly fatal disease, Anna pleads with him to make sure that she doesn't die alone.