The zombies pushing their way into the room paid no attention to the rope or the harpoon lodged in the wall. In their attempts to catch Brennan, they stumbled into the rope and became snared. As more and more zombies filled the room, the pressure on the rope was too much for the harpoon to handle, and it broke free from the wall.

Brennan was most of the way across when the harpoon let go. The tightly strung line of rope suddenly went slack, and he had to hang on for dear life as the tail end support dropped away. Because the far end of the rope was still secure, Brennan swung across the zombie filled street and slammed into the side of the building where it was attached.

Pain exploded in his left shoulder and arm as he struck the unyielding concrete wall, but it was a price he willing paid to escape the undead. Grunting with effort, he climbed the rope to the top and heaved himself over the edge and onto the roof.

"Glad you made it," the young woman said to Brennan in greeting, quickly collecting the rope and stuffing it in a well used backpack she wore. "We need to keep moving, are you able to travel?"

Brennan nodded, unsure what to say. He didn't know where this girl had come from or how she'd managed to save him the way she'd done, but he wasn't about to question it. Her brown hair had been pulled back in a ponytail, but the natural curls of the strands cascaded down her back and shimmered in the sunlight with ever step she took. She looked like an angel to him, and having rescued him from Hell, Brennan would follow her wherever she wanted to go.

Appearing to be in either her late teens or early twenties, Brennan's rescuer seemed perfectly at home as she ran and jumped off the roof to the top of the next building. Her attire consisted of an old pair of blue jeans, worn to bare threads in several locations, a formerly white shirt in only slightly better condition, and a pair of rugged boots looking sturdy enough to last forever.

A bundle of arrows was strapped to the outside of her right leg, and a small bow was buckled to her left. A dented metal canteen rode on her belt, and a light pack rested on her back. She smiled over her shoulder at him as they traversed the concrete landscape of the city rooftops. The young woman looked the part of someone perfectly at home in the broken remains of the world, and it bothered Brennan slightly.

He assumed his initial trust of the woman came from her rescuing him, but as the stress of nearly being eaten alive wore off, he started being suspicious of her. She seemed too at ease, and no one should be comfortable with had happened in the world. Too many had died; too many were undead. She reminded Brennan of himself, back before everything went wrong and he was still enjoying the adventure. Brennan couldn't trust someone who remained unscarred by the world. If she didn't really know what was going on, she wouldn't see threats coming and might become a liability to him. Following along, Brennan kept an eye out for an opportunity to part company and go his own way.

"Check this out," the woman bid to him, gesturing over the side of the building where they'd momentarily stopped.

Brennan humored her and looked down where she'd indicated, and the sight made him go cold. Every street below them was filled with the undead. They were packed tightly together like a mob of shoppers waiting to get inside a store for the first of the holiday sales. Moving a few steps to his left, Brennan got a look at a cross-street and found it in a similar condition. Every road in the city was filled to capacity.

"I've never seen so many," Brennan breathed in terror.

"They came here because of Sanctuary," the woman explained.

Brennan looked toward her, about to ask her what Sanctuary was, but he stopped as he noticed something strange. A grove of trees was situated atop one of the buildings, extending their long branches out over the edge of the roof to shade the street below. As he changed positions for a better view, Brennan saw many trees on the building roofs. He also noticed thin cables strung between some of the structures, resembling an incomplete spider web. As he watched, a figure jumped onto one of the cables and slid down and across to a building on the opposing side of the street, vanishing through an opening where several windows had been removed.

"What is this?" Brennan asked in amazement.

"We call it Sanctuary, and it's my home," she answered. "Come on. I'll show you around."

She led him to a different side of the building before pulling out a long rope and grappling hook. Spinning the hook in a circle, she hurled it upwards and caught the edge of a neighboring building. Almost immediately, a man armed with a bow and arrow appeared and looked toward Brennan and the woman. She waved to the bowman, and he waved an acknowledgement in return, turning away and continuing his patrol.

"You have the buildings watched?" Brennan asked.

"We have to," she confirmed. "Although we've secured the buildings from the undead, violent members of the living could still threaten what we've built."

"How do you keep the zombies out, especially this many of them?" Brennan questioned.

"I'll show you," she promised, handing him the rope. "Climb up to the roof. I'll meet you there."

"Where are you going?" Brennan asked.

"Shortcut," she answered with an easy smile. Producing another rope and grappling hook from her pack, the woman threw it to the top of the neighboring building and latched on with perfect aim. Sprinting along the edge of the rooftop, she jumped off and swung out wide at the full reach of the rope she held. When she passed near an office building, she managed to take several running steps along the steel and glass facade before kicking off to swing around and vanish behind the corner of the structure where her grappling hook was attached.

Brennan remained frozen temporarily in a state of disbelief. He'd been on the run for years, surviving on scraps, and yet, here was a city not only surviving but thriving in the middle of a sea of undead. It seemed too incredible for him to believe. Shaking himself out of his thoughts, he hung onto the rope and swung across the the building his rescuer had vanished behind, using his boots to halt his momentum when he reached the reinforced glass of the front wall. The impact was hard, but Brennan had been through worse. Keeping his feet braced against the wall, he began climbing.

***

"If you're going to stay here, you'll want to learn the quick ways of getting around," the woman suggested as she grabbed Brennan's shoulder and pulled him up and over the edge of the roof.

Brennan couldn't answer as the long climb had taken much of the air from his lungs. His hands had been worn raw by the rope, and he flexed them gently to relieve some of his discomfort. While he recovered from his exertion, Brennan examined the strange surroundings.

Trees lined the perimeter of the roof and were spaced evenly across its width so the branches of one would not interfere with those beside it. Placed in large boxes of soil, the trees were elevated off the surface of the roof so any excess water that might drain out could run off and evaporate rather than leak through to the floors below. Wooden scaffolding had been constructed around the trees for workers to climb up and harvest the wide variety of succulent fruit hanging from the branches.

Although well concealed in their green camouflage, Brennan noticed three men armed with bows keeping a careful watch. He only noticed the forth when he shifted slightly on a low branch of one of the trees. The idyllic setting was well protected, despite its lofty and nearly unreachable locale. These people were taking no chances.

"Who are you, and how did you ever manage to set this up without being overrun?" Brennan asked in total bewilderment.

"For starters, my name is Clara," she explained, taking a seat next to Brennan and flipping the dark curls of her ponytail over her shoulder out out of her way. "My dad started Sanctuary, using his skills in demolition to blast out the stairs in the lower levels of several buildings and preventing the undead from climbing up. He'd brought potting soil and seeds, and along with a few other items, established everything we needed to start a self-sufficient colony in these reclaimed buildings."

"Clever," Brennan said admiringly of the unconventional strategy. "How long have you been up here?"

"Ten years, back when the zombies first showed up," Clara explained. "We've been finding survivors here and there, like yourself, and bringing them back, adding to our numbers. The more of us there are, the faster and more effectively we're able to clear buildings and establish new havens for our fledgling community."

"You take people in?" Brennan questioned.

"Sure," Clara confirmed. "Unlike the town of Walton, our space and available resources aren't limited but expanding."

"You know about Walton?" Brennan asked.

"We've pulled several of their scouts out of precarious situations," Clara explained. "Since you know about the walled city, I assume you're one of their scouts too."

"Yeah," Brennan acknowledged. "I've been having to travel further and further for supplies, but it's the only place around where I can get a night's sleep while knowing for certain I'll wake up safe the next day."

"You can find that peaceful rest here," Clara promised.

"Where do you get the dirt for all the trees?" Brennan inquired.

"One of the buildings had a basement," Clara told him. "The main floor access point was blocked by a vault style door, but a private stairwell for the executives allowed an alternate route down. We broke through the floor and started digging tunnels. We have passages like an ant colony under the city, but they're rigged at key points to collapse if the undead breach them, and we have a twenty-four hour guard on the basement room itself. If the undead do find a way in, they won't get far before we blow the place and burry them."

"Sounds like you've thought of everything," Brennan complimented.

"No," Clara denied seriously. "We're always looking for things we've missed. It's the only way to keep ahead of the zombies. If we don't find the weak points, they will."

"What's that smoke?" Brennan asked, pointing to a plume of black several blocks away.

"We call it the fire-pit," Clara stated. "We frequently snag the undead in the streets with either nets or hooks. After killing them, we burn the remains. Over the years, we've taken out a multitude of them, but as you saw down there, their numbers are still thick."

"Are you making a difference in the grand scheme of things?" Brennan queried.

"Absolutely," Clara replied with unshakeable confidence. "The city may be filled zombies, but how many have we cleared in these ten years who will never threaten another living soul? How many new ones show up here, trying to reach us, rather than hunting people out there? We thin their ranks every single day. As my father told me once, the zombies are slow, but they overwhelmed the world because they never give up. We never will either, and because of it, we'll outlast them and take back the world."

She slapped him playfully on his knee before getting up. "You rested enough? There's so much I want to show you, but you'll need to check in with my dad first."

"You're not allowed to show someone around unless your dad approves of them?" Brennan joked.

"This isn't a date," Clara corrected. "My dad's in charge around here. If you want to stay and be a part of this, you'll need to talk to him. He can answer your questions about this place, everything we're doing around here, and how you can fit in."

"Okay," Brennan agreed as he stood. "Let's go see your dad."

Clara led the way downstairs.