After Jack and Mike rushed to the air-raid shelter in the center of the park, they stood in front of the entrance, which was about two meters high and wide. The thick, intricately crafted iron door at the entrance gave off an impression of being nearly indestructible.They approached the door and noticed that it wasn't locked, nor did it have any visible seams—just a solid, unyielding presence.Jack began inspecting the door for any clues. Since the card was supposed to be the key, it made sense that the black card he held would be the one to open this iron door.After some searching, they finally spotted a symbol matching the one on the card to the right of the door. There was no slot, so Jack simply pressed the card against it.[Identity verification successful. Opening.]A mechanical sound emanated from the door, and then, miraculously, it opened on its own."Let's go in," Mike said, gesturing toward the entrance.As they were about to step inside, Jack, always cautious, instinctively turned his head for a quick check behind them. And to his surprise, he saw a woman following them—quietly, almost unnoticed.Mike, noticing Jack's shift in attention, turned around. Upon seeing the stranger, his military instincts kicked in, and he was about to take action, but Jack stopped him.The woman had managed to follow them without being detected, indicating she was highly skilled at hiding. However, Jack didn't sense any malice from her. Even if Mike was trained in combat, there was no immediate need to escalate things.If she had been planning anything malicious, she would have acted by now. So, Jack calmly held Mike back as the woman approached.The iron door closed automatically behind them with a faint hum.Jack and Mike stood tensely against the wall, watching the woman as she advanced.As the three of them switched on their flashlights, they saw a staircase leading down into the darkness. Jack couldn't help but notice that the woman's silver hair stood out like a beacon in the dim tunnel. Even in the dark, her delicate features were clear.Despite the smile on her face, there was something dangerously calm about her. In the confined space, she maintained an air of nonchalance, yet her eyes never left Mike, as though she was calculating her next move at all times."So... I'm Jack, and this is Mike. What should we call you?" Jack asked, trying to break the tension.The woman chuckled softly. "Heh, you can call me Sakura. Don't be scared."With that, Sakura casually stepped to Jack's right, reaching out to brush a lock of his hair away from his face.Jack instinctively tried to step back, but he quickly realized there was nowhere to move. Sakura had positioned herself strategically, trapping him between herself and Mike. Even if Mike wanted to take action, he'd have to first navigate around Jack."How about this... the three of us team up and head forward together? Let's see what's ahead," Jack suggested, trying to break the awkwardness.Mike didn't budge, though. He continued to observe Sakura closely, clearly on edge. He didn't trust her yet. Sakura glanced at both men, then smirked before leading the way down the stairs.As Jack followed behind, the faint glow of his flashlight illuminated Sakura's military-style backpack, and a knife was strapped to her waist. At first, he thought she might be a soldier, but he quickly dismissed that thought."Sakura, you're only carrying one backpack. Do you think that's enough gear?" Jack asked, genuinely curious about her minimal load."Hahaha… you don't really believe the apocalypse is happening, do you?" Sakura chuckled, walking ahead of them.Jack couldn't argue with that. After all, there was no solid evidence to support it.The three of them walked for a long time, finally reaching the end of the staircase. Jack had counted 1,024 steps, with each step about 20 cm high, so they had descended over 200 meters underground. Even so, the air here was still fresh, likely due to a ventilation system.Ahead of them was another iron door, similar to the first. Jack was about to place his card in front of it when Mike stopped him."Hold on!" Mike pulled out a handgun from his backpack.Jack froze for a second. Although he had suspected Mike was military, seeing the gun caught him off guard. After all, he was living in peaceful times, and he had never seen someone openly carrying a real weapon. If something happened here, no one would know.Jack nervously asked, "What's going on, Mike?"Mike appeared uneasy as well. Even a trained soldier would feel some trepidation when faced with the unknown.Then Jack noticed something that made him tense up. Sakura now had a handgun in her hand too."Great," Jack thought. "Now I'm the only one unarmed?" But he quickly considered the situation from a different angle—if the two of them weren't going to harm him, then maybe they were his best protectors in this unpredictable scenario. After all, if danger struck, they would be in it together, and if things got worse, he could always try to make a deal."Ready? I'll open it," Jack said, as he placed the card on the scanner.[Identity verification successful.]A mechanical voice echoed, and the door opened.Inside, to their relief, there was no danger waiting. Instead, there was an elevator.Jack scratched his head and pulled a rope from his bag, tying a bottle of water to the end before tossing it inside the elevator to test for traps.When nothing triggered, Jack cautiously stepped into the elevator, followed by Mike and Sakura.Inside, the elevator only had one button, with no other options. The door closed, and the elevator began moving. The lights inside were dim, and it was hard to tell what direction they were going. All they could do was stand in silence, each of them quietly sizing up the others."Hey, Mike, Sakura, how about we put the guns away? We're all stuck in this together, might as well try to get along. Who knows, we might need to watch each other's backs," Jack said, forcing a small laugh.Mike and Sakura exchanged a glance. After a moment, Sakura smiled."Fine... you go ahead, Jack," she said."Alright, I'll lead," Jack said, resigning to his position at the front. He didn't have much of a choice, and he knew it.About ten minutes later, the elevator made a soft chime, signaling they had arrived at their destination. The moment of relaxation was over, and the three of them quickly turned toward the door.When it opened, they were greeted by the sight of a massive underground facility. Armed guards patrolled the area, each holding an automatic rifle.The space was vast, and there were dozens of people gathered in one area, most likely waiting for something.Jack stepped out first, determined to get to the bottom of what was happening here."Hey, hey, hey! New guy, back of the line! Can't you see we're all waiting here?" someone from the crowd called out, pushing Jack back.