The bottom of the Pacific Ocean near the Mariana Islands, above the Mariana Trench.

The Nautilus exploration submarine, which is part of the Pacific reconnaissance detachment of the BPRD, is on patrol duty. Captain Seth Tien hadn't slept well for three days and three nights since the anomalous energy signal was detected in the area, and he was now as irritable as a bull, whining at his crew at the slightest mishap.

"Captain, what would you like for lunch today?" asked the cook on board, tremblingly.

"Are you a pig's head?" Seth yelled as he pounded his hand on the button-strewn console in front of him, "Eat, you know how to eat! If you want to eat so much, then I can ask you to go outside and drink seawater, and keep it for you to drink!"

The cook was so frightened by the furious captain that he almost fell to the ground, and he did not dare to say another word when he saw Seth screaming in a rage, so he quickly ran away, lest he really throw him out into the sea.

"It's not good for you to do that, Captain. Jon Stadt, the Nautilus's chief of staff, couldn't help but remind. "Although this task is very boring, after all, it is an order from above, and no matter what, I can't blame my own people. ”

"I know that, Jon. Seth's tone didn't soften in the slightest, "But they didn't even tell me what we were looking for, so that they wouldn't make me angry!?"

Jon reached out and patted Seth on the back, and reassured him, "I know you're in a bad mood, don't worry, we'll settle this account with them when we get back, and they owe us an explanation anyway." ”

Seth muttered from his throat: "This is simply not a human errand, it is not allowed to float for three consecutive days, all rely on the oxygen circulation in the boat, and if it goes on like this, not only me, but even those sailor boys may not be able to survive in the future." ”

"Wait, if there is no movement for another six hours, we will immediately apply for evacuation, to be honest, I haven't seen the sun and breathed fresh air for the past few days, and even I feel like I can't bear it. ”

"Then do as you say. Seth's originally tense expression finally relaxed slightly, "When we go back, I must ask the above for a group vacation, and then the two of us can have a good drink." ”

Jon nodded in agreement, "Don't forget that you said it yourself, don't make me pay for it then, you pretended to be drunk the last time you invited me for a drink, and not only made me pay for the drink, but also asked us to pay for a taxi for you." ”

"Hehe, is there anything else like this?" Seth said, touching the back of his head, "I must have invited you this time, you can rest assured, rest assured to drink, no matter how much you drink, I will pay for it." ”

As they were laughing and joking, the Nautilus's hull shook violently, and the impact was so hard that Jon and Seth staggered.

"What's going on?" Seth shouted into the monitoring stand.

"Captain, there's something out there, it's fast!" replied the Monitor, staring at the surveillance screen.

"Immediately confirm what it is, lock it on with sonar. Jon stood up with his hand on the handle, and gave the order calmly.

"No, Chief of Staff. "It's too fast for us to lock, and the sonar can only tell us there's something, but we can't track it." ”

"Idiot, let me come. Seth pushed the Monitor away, rolled up his sleeves and prepared to go into battle himself. "Turn off the hull sonar and prepare to launch the blasting detection sonar flotation. He yelled and ordered.

"But Captain. The monitoring soldier who was pushed away said with a look of disbelief. "If we turn off the hull sonar, we won't be able to detect it. ”

"Shut up, hairy boy," Seth roared, his eyes not taking his eyes off the monitor at all, "you know what, sailor, if we can't lock it on with sonar, you're going to have three more submarines useless, and now we're going to take a gamble." Now turn off the sonar as I said, and then turn on the launch bay that probes the sonar floaters!"

The monitor hurriedly turned off the hull sonar according to his order, and then went to the lower control room to open the launch compartment.

"Do you want to do it yourself?" Jon asked as he looked at Seth with both hands clenched on the launch joystick.

"Of course I'm going to do it myself. Seth replied aloud, "Because this is my ship, and it's all our ship, and I'm going to protect it all as his captain, so I have to do it myself." ”

"The launch compartment is ready and ready for launch. A voice came from the lower tail control room.

Seth took a deep breath and asked, "Where was the sonar last detected it?"

"It's on the port side at 31°, southerly. ”

Is it 31 degrees on the port side, which is southerly? Seth silently calculated in his mind, then the target of his attack was the tail engine, and if so, the next attack would definitely appear within a range of no more than 90 degrees. It knows that with its speed we can't lock on, then it must think that we are helpless, so its next blow must be the most fatal one, and if it wants to be fatal, then it is most likely to attack in the direction of ......

His thoughts suddenly cleared, and he shouted to the lower control room: "Open the launch bay above the hull, quick!"

Jon asked him, "How did you know it was coming from above?"

Seth smiled back confidently: "Because it wants us to sink to the bottom of the sea forever, the most effective and safest way to attack is to attack directly from above." ”

"The launch bay has been opened, Captain!"

Seth could hear his heart pounding, and he struggled to adjust his breathing, then closed his eyes and listened to the sound of water pressure outside through the compartment.

It's already in place, Seth thought to himself, it's getting closer and closer to us, the sound of this pressure is 500 meters, 300 meters, his palms oozing sweat, come on, come on, get closer, it's 150 meters now. Soon, soon, 100 meters, closer, closer.

50 meters, yes, right now. Seth snapped his eyes open, then pressed the launch button.

Although only a few seconds passed, it seemed as long as a century to the people in the boat, and finally a point of light suddenly lit up on the central display, which had nothing in the past, and everyone cheered at this time.

"You succeeded. Jon said.

"Ah, we've got him. Seth wiped the sweat from his palms with his sleeve. "It probably startled it with that blow, so it gave up the attack, but the floating sonar was already fixed to it, and now we just had to track it. ”

As Seth said, the point of light did not continue towards the Nautilus, but quickly left and headed for the depths of the trench.

"Are we going to keep the pursuit? Seth. Jon asked.

"Of course you have to chase it. Seth turned his head back to the Monitor and said. "Otherwise, we're here for nothing, and besides, this guy just wanted to kill us, we have to find out what it wants to do. ”

The Nautilus re-entered the deep dive state from its original stationary state, closely following the point of light. And just below them, in the depths of the ocean without any light, the bottomless trench is like a greedy mouth waiting for its prey.