Genesis: Arisen, Book 0.5

Tucked away in a high-tech Tactical Operations Center, inside an isolated safehouse in the Horn of Africa, sits Agency analyst Zack Altringham. He is Kenyan-born, Princeton-educated, badly burnt-out - and condemned by his language and cultural skills to a lifetime of fighting America's shadow counter-terror wars. But when another mystery epidemic breaks out, terrifyingly quickly it reaches a tipping point and chaos descends - and Zack and his team (including two former Team Six SEALs) are trapped between the millstones of the sick and the dying on one side, and heavily armed militias on the other. Soon their "safe" house is in flames, and their only remaining option is to get in their up-armored SUV and try to escape the imploding gravity well of the city, to the safety of the American military base in Djibouti. But by then, will there be anywhere safe left on Earth to escape to?