---
The Vanguard slipped below the waves at 0430, a whisper in the vastness of the black sea.
Reeve monitored her descent from the Tactical Submarine Control Suite, a newly installed module inside Fort Sentinel's central command tower. It was quieter than the CIC—no chatter, no foot traffic. Just sonar tones, vector overlays, and a red light glow that cast shadows like scars across the walls.
> MISSION: SHADOW HUNT Objective: Probe Sigma Trench Asset: SSN-001 Vanguard
Route: Sentinel → Mu-3 Deep Corridor → Sigma Trench Shelf
Threat Level: Unknown
Projected Duration: 12 Hours (Round Trip)
---
Below, Vanguard operated in near silence.
Her nuclear reactor was small, compact—purpose-built for sustained patrol, not brute force. The acoustic baffles surrounding her propeller assembly minimized wake, and her hull coating absorbed sonar pulses like black velvet.
Lieutenant Mara Kwon again took point aboard, acting as human interface officer while the AI helm managed systems.
At 0620 hours, Vanguard crossed into Sigma Trench.
Immediately, the water grew colder. The soundscape changed.
Sonar pings returned distorted, like echoes bent by something dense and ancient.
---
> DETECTION: UNKNOWN SUBSURFACE STRUCTURE
Proximity: 2.1 NM
Configuration: Inverted Dome + Radiating Blades (14)
Material: Ferrite-Carbon Lattice (Non-Standard Alloy)
EM Emissions: Intermittent (Cyclical Pattern)
Kwon narrowed her eyes. "That's not volcanic."
"No," the AI voice responded, neutral. "It is engineered. Possibly dormant. Possibly listening."
> SUGGESTED ACTION: Bypass Structure | Observe Passively | Log Coordinates
But the moment they changed heading, Vanguard received an active sonar ping.
Loud. Deliberate. Not natural.
"Contact?" Kwon asked.
Another ping. Then a new contact appeared on the tactical overlay.
> CONTACT: UNKNOWN SUBMERSIBLE Length: 75m Speed: 12 knots Bearing: Direct intercept Armament: Unknown Origin: No registry data
Kwon immediately activated passive defense measures.
"Silent running. Adjust depth—let's vanish."
But the contact mirrored the dive.
---
Back at Fort Sentinel, Reeve's screens lit up with alerts.
"Incoming submerged contact," Keira announced. "They're being hunted."
Reeve clenched his jaw. "Arm tubes one and two. Let's see how they handle a cold war doctrine."
---
Inside Vanguard, the torpedo tubes flooded. Two Spearfish-class torpedoes—smart, wire-guided—loaded silently.
At 30 meters below the target's level, Kwon gave the command.
"Fire."
The torpedoes lanced outward, trailing microbubble cavitation. One struck amidships, detonating beneath the unknown contact.
The sea trembled.
A plume of metal and pressurized gas rose toward the surface.
---
> TARGET NEUTRALIZED Recovery Value: Partial (Hull Fragments, Black Box Core, Hybrid Propulsion Debris) Classified Entry Created: "Deep-Origin Drone Type A"
---
Kwon exhaled.
"What the hell was that?"
The AI responded:
"Not human. Possibly autonomous. Pre-collapse origin likely. Defensive drone, triggered by perimeter breach."
---
At 1900 hours, Vanguard returned to Sentinel waters. Reeve was waiting on the drydock platform.
The sub surfaced like a beast returning from the void, scarred but intact.
Kwon emerged from the conning hatch. "We weren't alone out there. That trench? Something's watching it. Something built to kill."
Reeve nodded. "And now it knows we're here."
---
That night, the Strategic Council met.
> LOG ENTRY CREATED: Deep Drone Threat Confirmed Recommended Action: – Expand Submarine Fleet – Initiate Counter-Drone Sensor Network (CDSN) – Assign Neptune-02 as Intel Packet Courier to Ironjaw and Echo – Increase Focus on Autonomous Warfare R&D
---
Reeve finished reading the last page of the recovered black box data.
It ended with a timestamp. Pre-collapse. A final line of system text:
> [DRONE WATCHDOG ONLINE. AWAITING SIGNAL FROM THE DEEP.]
He stared at the line for a long time.
Then he activated the R&D tree.
> BEGIN RESEARCH: DEEP-SEA WARFARE PROTOCOLS – TIER I
Somewhere out there, beneath pressure and darkness, a hidden war had already begun.
Now, Reeve would fight it.
---
[End of Chapter Twenty-Four]