You were working with Frank Woods's Rogue Black Ops Team in order to discover what "The Cradle" truly was. So you, Marshall, Sev and Case went to the lab in Kentucky in order to find some answers. As you 4 approach an elevator shaft, You, Sev and Marshall were able to jump across it easily. Case however... Wasn't so lucky... The ladder he grabbed broke off and he fell into the deeper part of the lab, inhaling some sort of gas...

Marshall: Shit! Case, do you copy!?

Case: My mask broke, I think I inhaled something nasty...

Marshall: Shit... Ok, try and find your way out. Stay sharp...

You did not hear another response from Case until about a few hours later. When he busts through the door of the server room, an insane, red glow in his eyes, as he pounced on you and began choking you!

Marshall: HOLY SHIT! WHAT THE FUCK?!