Zack drove the bus into the final town as Jamie brought the map out to find the hidden entrance to the tunnel that led to the sanctuary city. The city was a human-sized mousetrap set up by the aliens to kill the remaining humans that managed to stay alive through the initial invasion.
This town was different; there were still remnants of walls lining the streets.
"Stop!" Shadick and Shelia yelled at once.
Zack slammed on the brakes, flinging the passengers on the bus forward before it came to a complete stop. Both aliens rushed to the front of the bus. Shelia pointed to a marking on the wall in paint that blended in with the wall's graffiti.
Their shout threw Joe and Carrie out of their melancholy, now scanning outside for whatever the two aliens had spotted.
"That marking," Shelia said, pointing to a blotch within a spider web. "That means trap. It's nearby. Be careful; there could be traps all the way to the tunnel as well as through the entire length of it. There might not even be a city anymore. There could be single traps ready to kill stragglers that are trying to follow the map to make it into the city."
"Scan the area," Zack ordered. "Tell me if you see any more markings."
Shadick and Shelia scanned the area while everyone watched them, waiting for a response.
"I don't see anymore; that's the only one I see right now," Shadick stated. Shelia concurred.
"I think only a couple of us should go into the tunnel when we find it; the rest defend the bus unless you want to walk all the way back to the bunker on foot," Zack stated. "I'll go. Anyone else want to volunteer to go with me?" he asked.
Shelia raised a hand. "I'll go with you," she volunteered. "There might be traps or more marks that I can try and help identify."
Zack nodded, then scanned the rest of his friends. But unfortunately, no one was brave enough to volunteer.
Not wanting to force his friends, Zack grabbed a pack, giving Shelia one also, and situated his machete and blaster, ready to defend.
Looking at Shadick. "Keep an eye out for zombies. You're the only one staying behind that can scent them when they're near," he said.
Shadick nodded. "Be careful," he said. "Something about this doesn't feel right."
Zack looked at Shelia, who nodded in agreement. "I don't like it either."
"If there are people down there trying to survive, I have to try and warn them," he said, his voice tense. He knew it was going to be dangerous and very difficult to get through to the city at the end of the map. He hoped Shelia was good at spotting any traps or markings because it could determine if he lived or died.
Together, Shelia and Zack headed to the large grate that the map indicated as the entrance to the hidden city. They pulled it open and slipped inside, using the bar ladder to descend into the tunnel.
Shelia tapped Zack's shoulder, pointing to a marking on the wall. "There is a trap nearby. Walk slowly, and watch your feet at every step. A trip wire could be hidden under the dirt," she informed him.
Zack nodded and began to move slowly down the tunnel, following the map.
With each step, it got darker and darker; the grate farther away, not allowing the sun to light the tunnel. They continued down the tunnel, one slow step at a time.
There was another mark on the wall, the same one as near the grate when they first descended into the tunnel. Shelia tapped his shoulder and pointed at the mark, neither saying anything.
Zack pulled a flashlight out of his backpack and scanned the floor and walls with it. Three feet ahead of them was a rotting corpse, a man who had fallen victim to one of the traps. His foot was still caught in the trip wire that released an explosive charge.
Carefully skirting around the corpse, they continued. Stopping at another marking, Shelia studied it. "I know this is one, but I don't know what it means," she confessed quietly.
Zack scanned the floor for disturbed dirt or very neat like it had been swept even, then he scanned the walls and ceiling. He didn't see anything at first.
Shelia and Zack spotted it at the same time. A round disk was near the crease of the wall on one side. Shelia bent down to examine it, finding a trip wire lining across to the opposite side of the tunnel.
They carefully stepped over it and continued.
After nearly an hour, Shelia grabbed Zack's hand, her body going tense.
"What is it?" he asked quietly, looking up at her.
"I smell zombies up ahead," she growled. "A lot of them, too many to fight."
They looked down at the map, realizing that the city was just up ahead. It was now a zombie city. They quickly turned around and rushed out the way they came, being mindful of all the traps they had passed. Shelia was still grasping Zack's hand as they rushed down the long, trap-infested tunnel.
An hour and a half later, the grate came into sight. Carefully skirting the last trap, they climbed up the barred ladder and out of the grate, their friends waiting outside the bus, weapons in hand. They looked overly tense, eyeing their surroundings as they walked closer.
Shelia sniffed. "I smell zombies out here, too."
Shadick was the first to see them approach. "Hurry up, zombies are headed this way," he called.
Zack and Shelia started to run toward the bus. Suddenly, Shadick started shooting at them. Zack looked behind them, seeing nearly two dozen zombies following. Looking down at the tunnel, he saw that the grate was still secure. It wasn't the zombies from the tunnel.
Zack and Shelia picked up their pace, shooting their blasters behind them, trying to whittle the large group of zombies down to a smaller number. It was difficult at a dead run. They kept missing.
Shadick and the others continued to shoot, giving them cover as they ran toward the bus.
Everyone waiting at the bus filed in, shooting through the bus's open windows. Carrie started the bus as the others kept shooting, their blasters hitting random zombies with each shot. The narrow door of the bus was wide open, waiting for Shelia and Zack to get in.
Shelia jumped into the bus, with Zack close behind. Carrie slammed on the gas and sped down the street, looking for the highway entrance. The zombies were on foot, unable to keep up with the bus. It didn't stop them from trying, however.
Joe moved from his seat, sitting next to Zack. "What did you find down there?" he asked.
Zack looked at his friend, who was still trying to avoid looking at Shelia, who sat beside him. "We found a lot of traps, and the city is no longer a human city; it's a zombie city," he explained. "If Shelia hadn't been with me, I would have died the first five minutes."
Shelia blushed, not able to help it.
"Where am I driving to, Zack?" Carrie asked her twin.
"Back to the bunker. If you see cars that can give us gas, stop so we can fill the tank and gas cans," he told his sister. Then turning to Shelia, he rested his hand on hers, looking her in the eye. Everyone was watching them. "Thank you for saving me," he said, smiling at her. "If it weren't for you, I would be dead right now."
Shelia didn't know what to say. She shrugged. "I just spotted the markings for the traps and smelled the city of zombies once we found it," she said, blushing. Her green-tinted skin darkened with embarrassment.
Carrie watched them through the rearview mirror. "Could the zombies be the attack on the city that your people planned?" she asked Shelia.
Shelia was too engrossed in watching Zack that she didn't say anything, not realizing she was asked a question. Shadick stepped forward a couple of seats to answer for her. "It makes sense. The zombies would do all the work if anyone made it past the traps," he told Carrie. "Not only would it take care of the people inside the city, but also anyone who tries to find it."
Carrie switched her gaze from her brother and Shelia and focused on Shadick. "Do you know what your people are going to try next?" she asked him.
He walked up closer, sitting in the seat directly behind the driver's seat. "I don't know; I left before they started planning anything. If I had stayed, I would have known. But, I didn't, so I have to guess just like you."
Carrie turned back to the road ahead of her. She couldn't help but glance periodically at her brother, his hand still grasping Shelia's, and then to Shadick, who seemed to be watching her nearly every moment since he saved her on that first day they met.