Sam watches for movement in the water. The shockwave of the concussive grenades caused plenty of worms to go belly up, but there's plenty more where those came from. He also keeps an eye on Bill who appears to be a little distracted by the chorus of voices in his head. "Kelly, is that thing almost ready?"
"Will be soon. 'Enter 16 digit confrimation code. Entering an incorrect code three times will disable the device.'"
"'Next enter the timer start value in the format HHMMSS.'"
"Three minutes?! Are you crazy?"
"Look, we dont have to carry this thing out. We can run out a lot faster than we came in... assuming nothing gets in our way... and I don't want to give the snakes enough time to figure out how to stop it."
"'Confirm the timer start value by re-entering the same value.'"
"Get the hell out of here!"
Alvin, Kelly, Sam, and Bill head for the exit, with Kelly in the lead, allowing her incredible memory to guide the way back to their impromptu entrance. Perhaps inspired by their sudden movement, the infected come pouring out of the shadows at the escaping group. Kelly levels her sidearm and fires off several rounds while Sam strafes a full clip from his SMG across them. Alvin keeps them at bay with his Desert Eagles and notices that Bill is lagging behind. As he starts to get cut off, Alvin yells to Kelly and Sam "You guys go on ahead, I'll cover you."
Sam reloads, "You need some help over there?"
"No, I'm fine. Just go."
As Bill becomes more winded, Alvin yells, cajoles, and shoves him down the hallways as they keep up nearly continuous gunfire. Once they clear the central sector, most of the danger remains behind them.
Sam and Kelly get to the entrance blasted open minutes ago, maneuver through the twisted rebar, and head for the truck. Jesse sits in the passenger seat, dazed and bloody, after having turned to truck around to face away from the mountain.
Gritting his teeth against the pain of shattered ribs, Alvin pushes Bill towards the exit. Bill grunts in pain as the rebar snags cloth and flesh. The delay allows the pursuing horde to catch up and, as Bill crawls down the tunnel towards daylight, Alvin throws himself backwards through the opening in the wall while unloading his pistols at the worm people. As he lands in the tunnel, the next shot on one of his guns causes the slide to blow off the back of the gun. The slide rebounds off the back of the tunnel, missing Alvin's head by inches. Ignoring the powder burns, Alvin throws away the rest of the gun and heads towards daylight.
Bill and Alvin jump into the car and Kelly punches the gas, launching them past the downed chain link fence and following the tire tracks back towards the road.
100 meters out. The truck hits 60 mph. Kelly reaches pavement and continues accelerating toward the highway.