Disclaimer: Adventure Time belongs to Pendleton Ward/Cartoon Network. Thanks to Rinney and Anna for proof reading. This is the second of two chapters that I've posted today, please make sure you've read chapter 28 first or this won't make much sense.

The first thing that Princess Bubblegum had felt when she'd found Flame Princess and her companions in the mine was overwhelming relief that eclipsed her anger completely. Her daughter was unharmed, not trapped in a rockfall or suffocated from lack of oxygen or otherwise injured. Finn and Jake seemed fine as well, but the candy princess didn't pay much attention to them, it was their fault Feuer had come down here in the first place.

When Bubblegum had arrived at Blacksmith Town, the first thing she'd done was grab the nearest townsperson– who had happened to be the forgemaster – then interrogate them about whether he'd seen her daughter. Surprised and intimidated by her obvious anger, Broo had quickly explained that yes, the fire girl had been there with Finn and Jake and had gone down the mine with them. Bubblegum had nearly exploded with anxious fury there and then, but instead she'd stormed into the mine, wishing that she'd gone with her instincts and implanted a GPS microchip in the fire girl when she was a toddler.

It didn't take the candy princess long to pinpoint their location using the sensors on her nightvision goggles. She hadn't needed to use the underground guidance system in centuries, but the heat and vibration detection was just as sharp as ever and soon picked up the distant hum of voices and Flame Princess' thermal signature. From the soundwaves it looked like the conversation wasn't panicked, which implied that everything was okay. And as she calmed down, Bubblegum reconsidered her initial plan to burst in and drag her daughter back to the surface. She was still furious of course, but if Flame Princess was okay then there was no need to humiliate her like that in front of Finn and Jake.

Tapping the wristband she was wearing, Bubblegum activated the stealth field and immediately vanished, becoming no more than a shimmering outline. She continued onwards more carefully, trying not to make any sound, then started in sudden fear as her goggles picked up a massive burst of heat deeper in the mine. Throwing caution to the wind, the candy princess sprinted towards its source.

By the time Bubblegum reached the place where the heat signature had originated, it had already cooled back down to a normal level – well, normal for Flame Princess anyway. As she reached the hole that Jake had made in the wall of the mine – wincing as she saw that it was completely unsupported – Bubblegum stepped through it carefully, and had to stop herself from sighing loudly in relief. Flame Princess was standing with Finn by a pit in the floor that looked like it had been melted into it, which explained the heat blast. The candy princess made a mental note to talk to her daughter about that later.

The two children were standing on a pair of tan paws that must have belonged to Jake, presumably the rest of the magic dog was somewhere down that pit. They both looked fine, not even bruised or scraped, and Bubblegum sighed softly in relief. She raised one hand to her wrist to deactivate the stealth field, intending to appear and demand an explanation, but hesitated at the last moment. Flame Princess had deliberately disobeyed her, and she was certainly in trouble… but maybe it was best to let her complete this adventure before confronting her. It would certainly boost the girl's confidence to know that she'd helped saved the mine and if Bubblegum interrupted her now that could do more harm than good in the long run.

So she watched instead as Jake emerged from the pit and the three of them blocked it off, feeling a surge of pride despite herself as Flame Princess expertly fused the loose rock into one solid piece. And the princess couldn't help smiling when her daughter giggled and blushed as Finn told her they couldn't have succeeded without her. Then she froze as the fire girl seemed to catch sight of her, looking directly at her with a slight frown. Remaining motionless, Bubblegum breathed out thankfully as Flame Princess looked back towards Finn, and slowly retraced her steps out of the chamber. Once she was safely out of sight and concealed by the darkness of the unlit mine tunnel, Bubblegum turned and sprinted back towards the surface.

o.o.o.o.o

The three adventurers reached the mine entrance half an hour later, blinking as they stepped out into the evening sunlight. Flame Princess' eyes widened as she looked at the position of the sun, realising that much more time had passed than she'd thought while they'd been underground.

"Oh Glob, my mom's definitely going to be looking for me by now!" the fire girl groaned despairingly. "I'm gonna be in trouble…"

"Why?" Jake asked with the same sly grin he'd had back at the Candy Castle. "All you did was come with us to Blacksmith Town, remember? You never went down the mine; you were up here waiting for us the whole time."

"Yeah, that's right!" Flame Princess brightened at the thought. "Yeah, she might be mad that I've been gone so long, but it's not like I'm not allowed to go outside by myself or anything. I'm not a baby any more. As long as she doesn't know I was in the mine then she can't get THAT mad, can she?"

"Uhm…" Finn stopped dead in his tracks as he saw Broo and Jorgen waiting ahead of them. And also saw who was waiting with them. "Iiiiiii… think she might know already."

Looking up, Flame Princess barely noticed the ogre and the Marauder, her attention immediately seized by the woman standing between them with her arms folded, wearing a crown and an ominous glare. "…oh. I'm in trouble, aren't I?"

"Oh yes," Princess Bubblegum replied, her voice icy. "You are in SO much trouble, young lady…"

o.o.o.o.o

Meanwhile, miles below the surface of Ooo…

Duke Auric of the Golden Realm hit the ground with a hard thud that knocked both the wind out of him, and his crystal-bladed sword from his grasp. He reached for the weapon desperately, but as his fingers brushed its hilt his wrist was seized in a grip that was literally iron as a heavy foot landed on his chest and pinned him to the ground.

General Thaddeus Kaine of the Iron Regions sneered down at his opponent as the golden man struggled helplessly beneath his foot, tightening his grasp on Auric's wrist as he slowly began to pull at his arm. "Pitiful," the general rasped. "Princess Argent put up a better fight than you." As he spoke, one of his lieutenants dragged the silver woman forwards, her wrists and ankles already bound in iron, and threw her down beside Auric. "And don't expect Cyprium or Tytos to save you, they're both retreating back to their realms. Not that it's going to do them any good," he added with a dark chuckle. "Stannum and Wolfram have already surrendered. Soon the Iron Regions will have conquered the entirety of the Metallic Lands."

Auric gritted his teeth as his arm began to stretch, the gold of his body much softer than the unyielding iron of Kaine. "No one kingdom can rule the Metallic Lands," he hissed between his teeth. "You're destroying a balance that lasted centuries!"

Kaine tapped his chin in mock-thoughtfulness as he pretended to think that over. "Now where have I heard that line before… oh yes, the former Lord Ferric of the Iron Regions told me much the same thing before I took his head off. He was weak. But he made a fine weapon, don't you think?" he added with a chuckle and a meaningful wave of the double-ended glaive he held in his free hand. "And since I'm going to be the new Emperor of the Metallic Lands, I think I'll need a crown…" Jerking savagely on Auric's wrist and twisting hard, Kaine tore the duke's arm off at the elbow, the metal joint shearing with a shriek that was almost as loud as Auric's.

Kicking the golden man aside, Kaine turned back towards his army as they lined up in serried ranks across the square where he'd duelled Auric, the Golden Palace behind him. He brandished the arm he'd torn from the duke over his head, liquid metal blood spattering across his shoulder and arm, and grinned as his soldiers cheered.

"The Golden Realm has fallen!" Kaine announced, his voice echoing though the small cavern that housed the palace. "So has the Silver Kingdom, and the Tin Barony and Tungsten Protectorate have both surrendered. Only the Copper Federation and Titanium Regency are left, and they can't hope to defeat us! For too long the Iron Regions have allowed the lesser metals to hold us back; first we take the Metallic Lands, then the entire underground!"

"You're mad!" Princess Argent shouted from behind him. She'd managed to roll closer to Auric, and was awkwardly trying to stem the flow of blood from his arm with her bound hands, moulding the ductile shreds of golden skin around the stump at his elbow. "Even if you could conquer the rest of the underground, what then? Would you move onto the surface?"

Swinging round to face the silver woman, Kaine grinned at her, his eyes bright with fanaticism. "Why not?" Turning back to his army, the general raised his voice once more. "First we take the Fire Kingdom and enslave the elementals to power our smelting furnaces. They fear water much more than we do, what's a bit of rust to us? Then the Gem Worlds and the Crystal Regency, if we can't shatter them then we'll use them as weapons! The Stone Lands will barely be a diversion, we'll carve them into blocks for the fortresses we'll build when we move to conquer the lands above, and none of those pitiful surface kingdoms will be able to withstand us. In fact, once we reach the surface, Grod himself could not stop us!" Throwing back his head, the iron general laughed, then sputtered as he was hit by a shower of gravel falling from the cavern roof overhead. "What the…" Looking upwards, Kaine's eyes widened as an insectile shape dropped from a hole in the rock to land directly on his face as feathery antenna whipped out to lash at his skin, burning like acid.

There were a few moments of shocked silence as Kaine's soldiers watched their supposedly invincible leader drop to his knees, clawing briefly at the large insect that had fallen on him as he screamed, then falling silent as his entire head was reduced to rust. His body remained in its kneeling position, rusting firmly into place as more of the insects leapt down from the cavern roof.

Staggering to his feet, Auric pointed at Kaine's body and shouted with as much force as he could muster. "Grod has judged your leader for his hubris and the crime of murdering his rightful lord! See for yourselves!"

The bravest of Kaine's lieutenants took one step towards his leader's body, only to freeze as it began to crumble. The head of the largest insect swivelled towards him to look at him with cold black eyes as its terrible, metal-eating antenna swished around its head like demonic whips. Just being near it made his iron skin tingle and with a shriek of fear, the lieutenant bolted into the sudden pandemonium that was the ignominious retreat of the Iron Army from the Golden Palace.

Sinking back to his knees with a long sigh of relief, Auric watched the creatures devour the greatest threat the Metallic Lands had ever faced. Argent moved over to kneel beside him, then recoiled with a startled gasp as one of the giant insects leapt at her, automatically raising her hands to protect her face. But all that happened was that her wrists began to itch slightly, and as she cracked one eye open she saw that the creature was devouring the iron that bound her arms, her skin had only tarnished slightly at the contact. "What in Grod's name are they, Auric?" she asked softly, her voice awestruck.

The Gold Duke could only laugh in increasingly lightheaded amazement. "Well, I've heard of them. Iron devils or something they were called. They eat iron." He held out his remaining hand towards the largest creature, its antenna flickered over his skin but had no effect and it paid no further attention to him. "But they've been extinct for centuries. So I really do think they're an act of Grod."

Argent considered that for a few moments, rubbing the tarnish off her freed wrists, then grinned slowly. "Do you think this act of Grod would send the Iron Army running from my kingdom as well?"

"Oh yes," Auric replied, slumping onto his back as the ragged remnants of his city guard emerged into the square in ones and twos, many supporting injured comrades. "I think the Iron Army is in for an extremely unpleasant surprise…

A/N: So not only have Finn, Jake and Flame Princess saved Blacksmith Town, they've also saved all of the underground civilizations of Ooo! And they don't even know it, ah well. Also, if you know where General Thaddeus Kaine gets his name from, you get an internet high-five.

In the next chapter, there may be both a slumber party and also panic...