Six secret operatives are the military's top experts in covert ops and rescue missions. But this elite special force doesn't exist - at least not in the public eye. No one knows where they come from or to where they return. The group gathers for the most dangerous, most difficult, and most important missions and often operates in extreme conditions. They are known only by their code name: Invisible Six. When a known terrorist attacks a US passenger jet, the CIA plans to retaliate with a drone strike. But Zumi proposes that they capture Viggo the Vulture alive to gain information on worldwide terrorist networks and weapons smuggling. The mission takes Invisible Six into the criminal underworld's darkest corners. Can Zumi and I-6 outsmart Viggo at his own game?