Ghost and Soap sit huddled together in the dimly lit, abandoned warehouse, the chill of the fading autumn air nipping at their heels. It had been months since they'd laid eyes on another living soul, let alone encountered any signs of civilization. The world outside was a desolate wasteland, reclaimed by the zombies that now roamed freely, their numbers dwindling only as the temperature dropped.

Ghost's brow furrowed as a strange sensation prickled his skin, drawing his attention to the intricate skull tattoo that adorned his forearm - the mark that had never reacted to anyone before. He glanced over at Soap, noticing the same look of confusion and disbelief etched across his friend's face. There was no way... was there?

"Did you feel that, too?" Soap asked, his Scottish brogue laced with a hint of disbelief. "I thought it was just the bloody chill givin' me the willies."

Ghost shook his head, his dark hair brushing against the fabric of his skull balaclava. "No, I felt it. But it's not possible... is it?" He stood up, his tall frame unfolding from the makeshift seat they'd constructed from old crates and debris. "There hasn't been another person around for miles."