CDC Scientist Gunn Shoreham struggles to find the source of an Ebola outbreak in the Mideast, as the countries accuse each other of bio-terrorism. He must redouble his effort when one member of his team shows symptoms of the gruesome hemorrhagic disease. He returns to his lab in Atlanta and discovers that his son-in-law, who had been in Baghdad, has come down with the disease.

As Gunn's world collapses around him, he determines that the most likely source for the disease is an American. His evidence is so tenuous and circumstantial, he realizes stopping the disease and catching the perpetrator is entirely up to him.