"Jack-O's location has been discovered"
"He's hold up in an area underneath Circ-City."
"Fortunately, our forces recently secured a routh that leads to this location."
"Your mission is to find Jack-O and eliminate him. He's the one responsible for causing our world's descent into chaos."
"The struggle between Vertex and Alliance ends today."
This is quite possibly the easiest mission in game and it is by far the easiest final mission in the game. Jack-O is damaged in that he is missing his left arm grenade rifle making him a lot less damaging. You're biggest threat is the KSRW and if you stay behind him, he's very easy to defeat. You should S rank this mission on the first try if you don't do anything stupid.