In west Africa right now, there are two kinds of countries: Those that have Ebola and those that do not. Liberia for instance, has reported more than 6,000 cases of Ebola and 2,697 people have died. Right next door, in the country of Ivory Coast, there have been zero cases. Zero. Ivory Coast would desperately like to stay in that zero category.  The solution that Ivory Coast has come up with to stay Ebola free is simple. Ivory Coast will shut down its border. It will stop trade with Liberia, stop commerce and stop people from coming in.  On a map, a border is a simple thing: A clear thick line. On the ground, its anything but simple. On the ground in Ivory Coast, there are vast parts of the border with no signs, no guards, and only a secret path through the forest.  Today on the show, we go to a tiny tiny town on the border between Ivory Coast and Liberia. On one side of the line, Ebola is raging. The other side is Ebola-free so far. We ask: How do you close a border? And can you really?