At Bolg's command, the Orc army fled into the tunnels dug by the Earthworms.
So when Luke arrived riding Smaug, he only managed to eliminate the Orcs who couldn't make it into the tunnels in time.
However, all the other Orcs, including Bolg, had entered the tunnels, preventing Luke from finding him.
Luke was somewhat helpless upon seeing this situation.
This Bolg was clearly even more difficult to deal with than his father, Azog; he immediately hid in the tunnels as soon as he saw the situation was unfavorable.
Smaug noticed Luke's expression and quickly tried to show off, saying:
"Master, it doesn't matter if Bolg hides in the tunnels, I'll just keep breathing fire into the tunnels and burn them alive inside!"
Luke shook his head: "Have you forgotten they still have an Earthworm? As long as the Earthworm is there, they can burrow anywhere underground. How far can your dragon fire burn?"
As for the idea of chasing them into the tunnels, Luke didn't consider it at all.
Once inside the underground tunnels, it would be the Earthworm's domain.
Perhaps Bolg was hoping he would chase them in.
However, not chasing them in didn't mean Luke had no other way.
He jumped off Smaug's back, came to the tunnel entrance, pointed his wand inside, and chanted with malevolence: "Infernal Fire~"
A small wisp of eerie blue flame spewed from the tip of his wand.
The flame was full of violent and evil aura, as if it were fire from hell.
As soon as it landed, it quickly began to devour all surrounding combustibles, including Luke, the caster.
Luke's expression turned cold, and with a forceful flick of his wand, he drew the flame back.
The flame seemed to have a mind of its own; knowing Luke was not to be trifled with, it quickly spread deeper into the tunnel, consuming everything combustible in its path.
The flame grew larger and larger, eventually condensing into a gigantic fiery python that filled the tunnel.
Luke immediately used an Exploding Bolt to collapse the tunnel entrance, blocking it, and finally breathed a sigh of relief.
What he had just cast was the most dangerous spell in the magic world, the Fiendfyre Curse.
As one of the advanced Dark Arts, the Fiendfyre Curse is an extremely difficult spell to control. The summoned magical fire continuously grows stronger and stronger. It can mimic the forms of various monsters and relentlessly pursue and consume anything combustible, including the caster themselves, without distinguishing between friend or foe.
Therefore, some Wizards with insufficient ability, when casting the Fiendfyre Curse, often cause harm to themselves because they cannot control the Fiendfyre and have not mastered the counter-curse.
Thus, even the most heinous Dark Wizards never dare to cast this curse lightly.
To date, the only exception is the Dark Arts master Grindelwald, who can freely control Fiendfyre.
He can even use Fiendfyre to distinguish between friend and foe.
Those loyal to him remain unharmed by the Fiendfyre, while those disloyal are directly turned to ash.
If not for a great Wizard like Nicolas Flamel, who, along with the Scamander brothers and others, exerted their full efforts, even all of Paris would have nearly been burned to ashes by Grindelwald's Fiendfyre.
Luke did not believe he possessed Grindelwald's ability to control Fiendfyre.
So, after releasing Fiendfyre into the tunnel, he immediately blocked its retreat.
Anyway, there were only enemies like Orcs inside the tunnel, so there was no need to worry about harming the innocent.
Smaug, having witnessed Luke casting the Fiendfyre, immediately constricted his pupils and retreated several steps, full of apprehension and fear.
"Master, what was that flame you just cast? Why does it make me feel so dangerous?"
Smaug felt that the flame was even more potent than his own dragon fire; if he were to get even a little bit on himself, even his hardest dragon scales might not withstand its scorching!
"That is Fiendfyre, also known as Devil's Flame or Infernal Fire. It can grow stronger by devouring everything, and without a counter-curse, it will continue to burn until it can no longer be controlled."
Luke explained simply.
Upon hearing this, Smaug grew even more fearful of the Fiendfyre. He had always been proud of his dragon fire; even the hardest armor and weapons forged by Dwarves, he could easily melt.
But now, this Fiendfyre truly lived up to its name, as if it were a flame from hell, possessing a power to destroy everything.
Thus, he held even greater reverence for his Master, who could cast such terrifying Fiendfyre.
If his Master had used this flame against him back then, he would probably have been burned to charcoal by now!
Thinking this, Smaug couldn't help but feel a surge of relief.
Luke, on the other hand, was unaware of Smaug's current thoughts; otherwise, he could only say Smaug was overthinking it.
If the Fiendfyre Curse wasn't so difficult to control, did Smaug think he wouldn't want to use it?
Having blocked the tunnel entrance, Luke did not linger there.
He had Smaug continue to attack the Orc army and their weapons, while he himself rode his broom into the air, waiting quietly.
Indeed, it wasn't long before a large number of frantic Orcs poured out of a tunnel entrance below.
They trampled over their companions' bodies, scrambling out of the tunnel as if something terrifying was chasing them from within.
The next second, accompanied by a tremendous roar, a Fiendfyre mimicking a Basilisk burst out of the tunnel,
instantly incinerating the Orcs who couldn't escape in time.
The Basilisk Fiendfyre, having emerged from underground, let out a hiss, like a demon breaking free from its cage, attempting to spread and devour everything around it.
Luke, riding his broom, rushed over and powerfully waved his wand.
"Get back in there!"
An invisible barrier pressed down on the Fiendfyre, forcing it back into the tunnel.
The Fiendfyre, having burned for a long time inside the tunnel, had become even more powerful than before.
It wildly twisted its fiery body, unwilling to be forced back, hissing and spewing Fiendfyre at Luke, attempting to break through the barrier.
Luke channeled his magic to suppress it, forcing it back into the tunnel, then immediately collapsed the tunnel, sealing off this exit as well.
Luke continued to wait.
Soon after, another tunnel entrance once again spewed out a frantic group of Orcs.
This time, Luke directly collapsed the tunnel exit in advance, trapping both the Orcs and the Fiendfyre inside.
Next, Luke, like playing whack-a-mole, blocked each tunnel entrance from which the Fiendfyre tried to emerge,
not allowing it any chance to come out.
After an unknown amount of time, a huge sound suddenly erupted several meters north of the Lonely Mountain.
Blue flames shot into the sky, and a ten-thousand-foot fiery python hissed continuously, as if proclaiming its escape from its cage.
Luke's expression hardened; he hadn't expected the Fiendfyre to emerge from the other end of the tunnel dug by the Orcs.
He immediately rushed towards that direction without hesitation.
As long as there was even a tiny bit of combustible material, even just a small wood chip, Fiendfyre would not extinguish.
If he ignored it, he feared that even he would be unable to suppress it later.
By the time Luke arrived, he saw that the Fiendfyre had already condensed into a several-hundred-meter-long Basilisk, furiously devouring and burning an Earthworm.
And Bolg and some Orcs, miraculously, had not died and were frantically dodging the Fiendfyre's pursuit.
However, before Bolg could be burned to ash by the Fiendfyre, Luke's spell arrived first.
"Diffindo!"
Bolg's terrified expression instantly froze, his body immediately sliced into countless pieces.
Dealing with Bolg was merely an incidental matter; Luke did not linger and swiftly flew towards the Fiendfyre Basilisk, his wand emitting dazzling light.
"Finite Incantatem!"
Finite Incantatem could be said to be the counter-curse for almost all spells; it could lift most curses within its area of effect, including the Dark Arts spell, the Fiendfyre Curse.
As Luke cast Finite Incantatem, the spell formed a huge barrier that enveloped the Fiendfyre, causing it to continuously shrink.
The gigantic Basilisk mimicked by the Fiendfyre furiously attacked the barrier, creating ripples and attempting to break free from its prison to burn everything.
Luke was struggling a bit at this moment.
Although Finite Incantatem was the counter-curse for the Fiendfyre Curse, its effectiveness depended on the strength of the Fiendfyre.
If it was newly cast Fiendfyre, this spell could easily extinguish it.
But the Fiendfyre before him now, having devoured the lives of tens of thousands of Orcs, had formed a hundred-meter Fiendfyre Basilisk and was already extremely powerful.
Fiendfyre of this intensity would require at least four or five elite Aurors to collectively cast Finite Incantatem to completely extinguish it.
Now that Luke was dealing with it alone, he was clearly stretched thin.
However, Luke did not intend to extinguish it completely by himself.
His goal was to force it back into the tunnel and then completely seal off that exit.
Although the Fiendfyre Curse could burn most objects, even steel was no exception.
But it wasn't truly unburnable.
Things like stone and earth could stop the spread of Fiendfyre.
So once the tunnel was sealed, the Fiendfyre could only burn within the tunnel, and once there was nothing left to burn, the Fiendfyre would naturally extinguish itself.
But clearly, the Fiendfyre, with its own consciousness, was not something that would obediently comply.
Seeing that its Basilisk form could not break through the barrier, the Fiendfyre actually mimicked the form of a Balrog from Middle-earth.
The Balrog looked like a demon from a past life, with a pair of curved horns on its head, a pair of bat wings on its back, and a long tail.
It held a flaming whip and forcefully attacked and lashed at the barrier.
The barrier immediately swayed violently, showing signs of being unable to hold up.
Luke's expression changed, and he immediately channeled his magic with full power.
"Get back into the tunnel!"
The barrier continuously shrunk, forcing the Fiendfyre Balrog to retreat.
The Fiendfyre Balrog was not a true Balrog after all, nor did it possess much sentience. Seeing itself suppressed, it slowly retreated back into the tunnel.
"Exploding Bolt!"
Luke was quick-witted and instantly struck above the tunnel.
With a violent explosion, the tunnel collapsed, directly burying the entrance.
Luke was still not at ease, so he cast several more spells, completely and securely sealing off the tunnel entrance, and only then did he breathe a sigh of relief.
Then he waved his wand, making Bolg's head float, and rode his broom back to the battlefield.
Meanwhile, on the battlefield,
the combined forces of Elves, Dwarves, and Men had already gained the upper hand.
Ever since Luke forced the Orc leader Bolg back into the tunnel and released Fiendfyre,
the Orcs on the battlefield had already suffered a great blow to their morale and their army was unstable.
Afterwards, the Great Eagles were summoned by Gandalf, bringing immense aerial pressure to the Orcs, causing the Orc army to collapse at the slightest touch and retreat steadily.
If not for the Orcs outnumbering the total of Elves and Dwarves by several times, making it impossible to kill them all at once, the Orc army would have already been routed like a landslide.
When Luke flew back above the battlefield, Luke threw Bolg's head down.
His voice, amplified by a spell, echoed across the entire battlefield: "Orcs, your leader Bolg is dead, you have been defeated!"
Immediately, he took out a black horn.
It was a horn made from the horn of some unknown animal, with spells inscribed on it.
This was something Luke had found on Bolg.
He somewhat disdainfully wiped the mouthpiece of the horn, then blew hard.
The horn emitted a piercing, highly penetrating sound that rapidly spread in all directions.
The next second, the giant bat swarm, which had been obscuring the sky, became chaotic and scattered, flying wildly in all directions, as if they had received an unknown command.
The dim sky quickly brightened again, and the sun shone once more upon the earth.
The Orc army frantically tried to find shade, but they couldn't hide in time and were struck by the sun.
Instantly, the Orcs collapsed to the ground in agony, losing their fighting ability.
And the Trolls directly turned into stone, their terrified expressions frozen on their faces.