Gondor and Mordor were mainly separated by the Ephel Dúath mountains, while the Ithilien region on the western side of the mountains served as a buffer zone between the two realms.
Ithilien bordered the Anduin River to the west, the Ephel Dúath to the east, the Dead Marshes to the north, and the Poros River to the south. It was one of Gondor's fiefs.
It had once been a beautiful and fertile region of Gondor, called the "Garden of Gondor," with Minas Ithil serving as an important city controlling the passages into Mordor.
But as Gondor gradually declined, the Ithilien region suffered long-term harassment from Mordor's forces and gradually fell into ruin. Minas Ithil was even occupied by Mordor and transformed into Minas Morgul.
For nearly a century, the Minas Morgul fortress had remained tightly guarded. Apart from occasional orc squads leaving the fortress to roam Ithilien, no large-scale wars had occurred.
But on this day, the orc armies in the Minas Morgul fortress came out in full force.
Even from the Cirith Ungol pass, where Minas Morgul was located, endless dark armies continuously poured from Mordor through the pass, crossing the Ephel Dúath toward Ithilien.
Among this orc army was the orc squad Kael had encountered when collecting giant spider Shelob's silk.
When Kael, disguised as an orc, had gone to Shelob's lair and never returned, the orcs at the watchtower assumed he had perished in Shelob's maw. After fierce competition, a slightly stronger orc became the new captain.
But before this new orc captain could enjoy his authority for long, he received orders to join the orc army in attacking Gondor.
The final result was that this orc squad, like other cannon fodder, died silently in the war between Mordor and Gondor.
Speaking of which, for Mordor's army to invade Gondor, they first had to cross the river.
The only place to cross was the great bridge of Osgiliath.
Osgiliath was Gondor's early capital, located on the Anduin River, spanning both banks with a great bridge connecting them, and divided into eastern and western districts at either end.
This great bridge had changed hands between Gondor and Mordor multiple times. Now the eastern district was abandoned by Gondor, which instead firmly defended the western district.
Since Gandalf came to Gondor and explained Sauron and Mordor's threat to Gondor's Steward, Gondor had stationed more troops to guard Osgiliath's western district against Mordor's invasion.
Though Gondor took border defense against Mordor seriously, having had no large-scale wars for so long, they thought things would continue peacefully.
Until this day, when they saw tens of thousands of orc troops sweeping across Ithilien and assembling in the eastern district across the river, crossing the bridge to attack the western district.
Only then did Gondor's garrison awaken as if from a dream, hastily defending while rapidly sending word to the capital for reinforcements.
The orc army scrambled across the bridge to the western district's gates, setting up ladders and attempting to scale the walls and break into the city.
Gondor's garrison sealed the gates tight, standing on the towers shooting arrows at the orcs below and pushing down ladders.
For a time, sounds of slaughter and screams filled the air.
Because Gondor's garrison held advantageous ground, mainly orcs suffered countless casualties, falling from the bridge into the Anduin River below.
The orc army's repeated charges were repelled by Gondor's garrison on the towers.
But before Gondor's garrison could breathe easy, at a signal, the attacking orcs retreated.
As Gondor's garrison waited anxiously, several massive trolls appeared carrying huge black iron balls, charging toward the gate through dense arrow volleys and piling the black balls at the gate.
These iron balls had burning fuses, sizzling continuously.
If Kael had been present, he would have immediately recognized this as gunpowder.
Obviously Saruman had taught gunpowder technology to Mordor, creating these explosives.
Gondor's garrison had never seen such things, but instinctive unease made them try to stop the trolls' actions.
But trolls had thick hides, and ordinary arrows hitting them were like pinpricks.
Soon, with a deafening explosion, Gondor's garrison on the towers felt the ground shake violently.
The solid gate was blown apart directly, and Gondorian soldiers behind the gate suffered countless instant casualties.
The orc army immediately let out savage cheers, charging again with weapons raised, attacking through the gate.
Inside the western district, Gondor's garrison and the orc army fell into fierce combat.
Gondor's garrison fought desperately, but under the fierce assault of orc armies continuously crossing the bridge into the city, they could only retreat repeatedly.
The western district could fall at any moment—the situation was critical.
Seeing this, the defending commander made a snap decision, ordering his troops to repel this wave of orc attacks at any cost, then destroy the bridge.
Under the commander's leading charge, Gondorian morale surged as they fought their way through, killing blocking orcs and rushing outside the city to battle orcs on the bridge.
Amid sounds of combat and screams, orcs and human soldiers fell into the great river below, swallowed by turbulent currents.
But ultimately it did not go as Gondor hoped—the charging Gondorian commander was hit by an orc's stray arrow and, along with his horse, tumbled into the torrent below.
Gondor's garrison also failed to successfully destroy the bridge's key supports to stop enemy advance.
With the loss of their commander, Gondorian morale plummeted. Routed by the orc army, they could no longer form effective resistance.
Finally, after fighting day and night, Osgiliath's western district fell to the orcs.
Thus the natural barrier of the Anduin River no longer hindered Mordor's army.
Mordor forces occupying Osgiliath could directly enter the Pelennor Fields west of the Anduin and then directly threaten Gondor's capital, Minas Tirith.
News of Osgiliath's fall was swiftly carried back to Gondor's capital by messengers.
Gondor's Steward was shocked, ordering full defense of Minas Tirith while sending people to light the northern beacon fires, calling Rohan for aid.
Gondor's beacon hills were built on outer hills flanking the White Mountains, seven in total. After the beacon near Minas Tirith was lit, the remaining beacons successively spread westward, yellow smoke rising to the clouds, visible from very far away.
In Rohan's capital, Edoras, King Théngel saw the yellow beacon smoke on the White Mountains.
But he could not spare aid for Gondor now.
Because Rohan also faced invasion—over ten thousand orcs had emerged from Mordor's northwestern Black Gate, mixing with Easterling armies and marching toward Rohan.
King Théngel faced a dilemma: by agreement, when Gondor lit beacon fires for aid, Rohan should send troops.
But now Rohan also faced threats and could barely protect itself—how could they provide aid?
Finally, the Rohan King could only send a thousand cavalry to aid Gondor and explain the situation.
Then he rapidly summoned armies from across the country to resist Mordor's invasion together.
"Your Majesty, we have a wizard neighbor to the west with Dunlendings under him. Should we request his aid?" the new Chief Counselor suggested to King Théngel.
King Théngel thought of the starlight phenomenon that had appeared for over two months and the Saruman spy Kael had exposed, leaving deep impressions of this mysterious and powerful Black Wizard.
He nodded. "I will personally write a letter and send someone at top speed to Isengard. If we can gain aid from this Dragon Lord, Rohan's crisis might be resolved."
He quickly wrote a sincere letter, and a messenger rode the fastest horse toward Isengard.
At Isengard, in Orthanc Tower, Kael and Gandalf learned of Gondor's invasion earlier than the Rohan King.
Because Gondor's Steward possessed a Minas Tirith seeing-stone, and Gandalf also had Saruman's palantír.
So Gondor's Steward directly contacted Gandalf through his stone, informing him of Osgiliath's fall and Minas Tirith's peril.
Learning this news, both Kael and Gandalf frowned.
Kael did not remember this happening in the original timeline—he recalled Mordor only launching major attacks on Gondor during the War of the Ring. Why was it happening early now?
This unexpected development made Kael feel strange and vaguely uneasy.
Gandalf was purely worried, his expression grave as he smoked his pipe, deeply puzzled.
"What change has occurred? Sauron's power should not have recovered yet—why is he suddenly rushing to attack Gondor?"
Unable to understand, Gandalf took a final puff and stood up.
He looked apologetically at Kael. "Sorry, Kael, I am afraid I cannot serve as your commissioner to formally court Arwen at Rivendell right now! I must immediately go to Gondor—absolutely cannot let Minas Tirith fall, or all Middle-earth's situation will be in danger!"
Kael was not surprised, shaking his head. "No need to feel sorry. The Rivendell matter is not urgent, and with Gondor in crisis, Lord Elrond probably shares this concern. Current circumstances are not suitable for marriage proposals. We can wait until you return before going to Rivendell."
Gandalf smiled. "Very well, once Gondor's crisis is resolved, I will personally go to Rivendell to help you win your beauty!"
Kael asked. "With Gondor in crisis, can you go alone? Do you need my help?"
Gandalf shook his head. "My going to Gondor is mainly to inspire Gondorians' courage and hope against darkness while organizing Gondor's armies against Mordor's forces, so I can go alone."
"Besides, I worry that during Mordor's invasion of Gondor, Saruman might seize the chance to reclaim Isengard, so you are needed here to guard against Saruman's attack!"
Hearing Gandalf's words, Kael did not insist further. After all, Gandalf was right—knowing Saruman as they did, when they had jointly pursued him and he had fled to Mordor like a stray dog, there was no reason Saruman would remain inactive during Mordor's advance on Gondor.