The Zika virus, first identified among humans in 1952 in Uganda, began spreading across the Americas and the Caribbean in 2015. Locally-acquired cases on the continental US are imminent. Considered a public health emergency by the World Health Organization, Zika can cause microcephaly and other severe brain defects in newborns and has been associated with Guillain-Barre syndrome, a disease of the nervous system, in adults. While mosquitoes are currently the primary source of infection, the virus can also be sexually transmitted. Can Zika be contained? Are systems in place to handle the likely global impact? How bad will it get?