Book excerpt: INFECTIOUS & CONTAGIOUS DISEASES. In the summer of 2003, a perilous helicopter descent delivers Ross Donaldson, an American medical student in his mid-twenties, into Sierra Leone. With abundant schooling but little practical experience, Ross wants to save the world. Little does he know that by the end of his journey, it is he who will need rescue. With rebels fighting just across the border in nearby Liberia to force the dictator Charles Taylor from power, humanitarian need quickly sweeps Ross southward towards makeshift refugee camps and the heart of danger. There, he has his first terrifying encounter with the Lassa Virus, a highly contagious Ebola-like disease. Eventually, he begins work at the Lassa Fever Ward, the only facility in the world solely dedicated to the treatment of this deadly hemorrhagic illness. He is wholly unprepared for what he finds, and for twist of fate that will see him running the ward alone, with only a handful of untrained nurses to help him.