675.Goryeo warships.
As the fog over the Murasaki River began to lift, the water flowed with a deeper, lower resonance than usual.
(kawa= river.)
The Murasaki River was a quiet river connected to the sea, and the farther it ran toward the castle, the narrower it became and the slower its current grew.
It was a channel for merchant boats and fishing craft.
It was not a route conceived for war.
That was why Kokura Castle had its back to the river.
That morning, too, the river ran as it always did, and the fog lay low, blurring the riverbank, the rise of earth, and the lower body of the castle.
The defenders on the ramparts were facing the sea.
Watching the ships that passed through the Kanmon Strait was a motion the castle had accumulated for a long time.
Then an unfamiliar vibration spread from the riverward side.
The disturbance of the current came first.
Then a heavy reverberation settled low over the water.
The sound of fitted timbers locking together, the rhythm of oars, and the flow of wind slipping past overlapped—
as if the river itself were making room.
"…"
A soldier by the bank turned his head.
Movement grew inside the fog.
What emerged first was not a prow, but a dark mass that filled the river's width.
The mist split as if cut, and a black hull rose out of it.
"A ship…?"
The word did not reach its end.
This was not the kind of movement the river ever carried.
Its height, breadth, and weight separated at a glance.
The pressure with which it cut the water was different.
The sail was down.
A few oars moved at slow intervals.
Its entry was slow, and precisely for that reason it looked stable.
"A ship like that… into the river?"
The vessel that came upriver was, at first, only one.
It rounded the bend as if it knew the way, revealing itself in full.
Immediately behind it—another, and another.
Goryeo warships.
At that moment, panels along the ships' flanks opened.
They moved slowly, without concealment.
From beneath the covers, black muzzles appeared one after another.
The ships had taken position broadside—
their sides set cleanly toward the castle.
"Artillery!!"
A short cry burst out.
"Fire."
BOOM!!
Flame, smoke, and impact spread across the river.
The naval guns did not strike the sea-facing walls.
They pressed precisely into the space between the riverbank and the Honmaru—
the dense zone where watchtowers clustered.
Stone leapt.
Bodies were caught with it.
A second blast layered itself over the first shock.
BOOM—!!
Water surged up and hammered the base of the castle walls.
The defenders needed time to understand the direction of the blow.
The pressure was not coming from the sea.
Not from the main gate.
It was coming from the river.
"Respond!"
Shouts spread, but movement could not find a branch to follow.
The axis of defense was built toward the north face and the sea.
The riverward side had been left as open space.
Meanwhile the ship-guns kept their cadence.
BOOM— BOOM— BOOM—!!
In the fog, another ship emerged.
Then another followed in line.
The river was no longer background.
It had become a corridor that opened the flow.
Inside the castle, eyes began to shift.
Not toward the gate—
toward the interior layout, which was shaking first.
This was not the sound that opened a fight.
It was a signal that the fight had already reached its ending.
Cutting through the roar, the ships continued to push upriver.
The sails hung half-lowered, and the hulls ran long, exposing their broad sides along the channel—
an angle the castle's sea-fixed gaze had never held.
The defenders received the sight a beat late.
"From the river—?"
Before the sentence could finish, the gun covers opened again.
"Load."
A short command.
The barrels aimed between bank and wall, avoiding the tenshu, choosing instead the outer edge of the Honmaru—
the zone where towers layered over one another.
BOOM—!
Water jumped, and soldiers on the stonework staggered.
The purpose of the fire was not destruction.
It was pressure—
to disorder direction.
BOOM— BOOM—!
Sequential shots followed.
When one blast sounded, the next load was already complete.
The castle was not ringed from the outside, yet inside it had less and less space to breathe.
"Respond!"
The cry came again, but movement lost its branches.
Arrows flew toward directions they could not reach.
Spearmen scattered to find an exit.
The main gate was distant.
The ramparts' sightlines could not catch the river.
Still the gunfire held its rhythm.
The boom of ship-guns pounded the walls, and smoke and fragments covered the riverbank.
Inside the castle, force and attention gathered toward the river as if pulled by gravity.
A commander's orders scattered on the roar.
Reports took time to climb.
Within that current of uproar, Park Seong-jin and Song Yi-jeong moved.
At the moment the guns boomed loudest, footsteps began on the opposite side of the castle.
The strike team numbered about twenty.
Light armor.
Weapons kept short and clean.
They did not climb the walls.
They seeped inside.
As water sinks into sand, they flowed along the gaps and entered.
The chaos by the river drew the watch outward, and the inner passages emptied.
Song Yi-jeong raised a hand.
"Now."
The team advanced on the beat of the artillery.
With each shot, they moved one sector.
Corridors and low passages that connected the interior were routes already familiar to their feet.
Song Yi-jeong went first, and at a single gesture the formation tightened.
Footfalls were short.
No excess remained in the motions.
Stairs appeared.
An interior stairway leading up toward the tenshu.
As the gunfire swelled to its peak, the team climbed.
The outer ring lurched, and inside the tenshu a brief pocket of breath formed.
Into that pocket, people entered.
A door opened.
Two took the left and right.
Song Yi-jeong stepped in first.
The tenshu interior was not yet where commanders had gathered.
Reports had not reached the upper levels.
Orders were still being sorted.
The strike team took the upper floors quickly.
From the highest point of the tenshu, Song Yi-jeong pulled down the banner.
Park Seong-jin confirmed the motion and stepped to the window.
The castle's internal routes lay visible at a glance.
The gunfire continued, and its vibration covered the whole fortress.
Park said,
"Now."
Song answered at once.
The instruction sent down from the tenshu was simple.
Over the river, the gunfire adjusted its cadence and continued.
A door opened.
Outside, the cannon shook everything.
Inside, no conclusion about how to fight had yet gathered.
The strike team filled that blank.
Song Yi-jeong climbed first and seized the tenshu.
"It's over."
It was not a proclamation.
It was a short report—
a confirmation of state.
Footsteps overlapped in the inner corridor.
Lightly equipped fighters and heavily armored guards appeared at the same time.
The distance between them was close enough to touch with an outstretched hand.
Action burst before instruction.
The first collision began at the edge of blades.
Song Yi-jeong stepped half a pace forward and drew his sword low—
a guard's waist split open.
Blood spattered the floor, and through that gap the team poured in.
Between the pillars of the tenshu—
a space not wide—
it became a battlefield in an instant.
The guards were many, and their gear was heavy.
Their movement was slow.
Their turning even slower.
The strike team paired off in twos.
One bound the gaze.
The other slipped in and cut the back of it.
Steel-on-steel rang in a chain—
short, fast sounds without interruption.
Late orders from the command side broke apart like shrapnel.
Only cutting remained.
Park Seong-jin straightened and extended his sword.
A pale, white sword-force flared from the tip and split the brow of the man rushing in.
Park slid aside like water, stepping beyond the opponent's turning radius, and struck the front.
Before the arc even landed, blood surged from the throat.
Park lowered his hand.
Song Yi-jeong nodded.
The strike team led the lord's family down below.
"It's cleared."
Park Seong-jin stepped back to the tenshu window.
Below, the gunfire was slowing its rhythm.
He could see the castle's movement gathering into a single line.
He said briefly,
"The flag."
From the upper level, Song Yi-jeong lowered a white flag of surrender.
The center of the tenshu sank into stillness, and the flow within the castle converged into one line.
Orders fell from above and spread like a wave.
In that moment, the air of Kokura Castle began to move differently.