It Hunts Us

E1

In this introduction to life on the front lines, doctors in the U.S. and Asia battle the flu, and researchers race to develop a universal vaccine.

Pandemic Is Now

E2

Vaccine debates rage while health-care workers inoculate against the Ebola virus in Congo and influenza in detainee camps at the U.S.-Mexico border.

Seek, Don't Hide

E3

Worldwide, scientists test animals and their handlers for emerging viruses. In the U.S. and India, doctors work long hours caring for flu patients.

Hold On to Your Roots

E4

Anti-vaccine debate escalates, and medical staff are attacked in Congo. Funding cuts hit hard in the U.S., but researchers in Guatemala make strides.

Prayers Might Work

E5

Around the world, community, family and faith help physicians and medical advocates stay strong in the face of long hours and a relentless disease.

Don't Stop Now

E6

Successes for some balance setbacks for others. Meanwhile, viral outbreaks continue to claim lives across the globe — and a larger pandemic looms.