The locomotive clattered onwards, shaking and rattling as it continued the out of control run up the cliffside gradient.
Its rods roared into a blur, the wheels spinning so quickly that their elegant, cast detail resembled flat red coins. Smoke and steam poured from the engine's funnel in a disorderly, sky dying cloud.
The Boggles were continuing their relentless leap of death, gleefully tossing themselves into a fiery doom and continuing to push the locomotive to its limits. If Dipper and Pacifica had time to look out of the soot-stained windows, they'd see its boiler looking strangely bloated, the mass of bright orange sparks peeling from the smokestack and, if they gave themselves a little time to think, may have worked out the issue with a red hot fire, a funnel and a tunnel before the sprinting steamer plunged into darkness.
The effect was instantaneous. Pacifica dove to Dipper's side and screamed as the air pressure from the tunnel pushed the fire out of the hole to the furnace. White-hot, scalding flames shot from the glowing firebox with a horrendous boom, coating the cab in a monstrous heat and threatening to incinerate everything it touched.
Immediately, the tunnel was illuminated in a brilliant orange glow. The locomotive screamed over the curves, its pistons scraping the walls as it threatened to overturn. Sparks flew. Steam whistled from every joint and gasket. The sound of it all reverberated from each side of the tunnel's walls and almost deafened the two helpless teenagers - a combination of a colossal iron stampede and an enormous pressure cooker.
The Northwest heir, soaked and sooty, grabbed the whistle cord to help balance herself - and, with an ear-splitting, mournful hoot, the engine whistled its plight to the town of Gravity Falls. It echoed through the tunnel, over the bridge, and swept across the town in a desperate plea for help.
WoOooOOooooOOO-OOOOoooOOOoooo
It was only natural, perhaps, that the townspeople didn't quite understand the intent of that deep, trailing whistle. People gathered out of their homes to see the spectacle of the locomotive chugging over the bridge for the first time in over a hundred years - and were somewhat startled, albeit completely untroubled, by how fast it was going.
"Do you think it's an express train?" Tyler asked.
"I always thought that express trains needed passenger cars." Tad replied. "But I'm no expert."
"Sure is picking up quite a pace." Bud sniffed, his hands in his pockets. "Quite a machine."
"Welp, I'm sure the driver knows what he's doing." Tyler giggled.
"I can't believe this is happening! We have no idea what we're doing!" Dipper yelled over the noise of the hammering machine.
The thundering of the locomotive was increasingly unbearable on the footplate. The fire fell back as it left the tunnel, leaving only dark scorch marks across the floorboards. The two kids glanced at eachother, caked in soot, singed and sweaty - and leapt up to close the firebox door, fighting against a hail of Boggles.
It didn't help that the whistle cord - that, for some unfathomable reason, was made of elastic - now dangled loose about six times its original length, swinging back and forth. It only made the route even more of a complicated hassle in the cramped little cab.
It tangled around Pacifica's waist, over her shoulders, under her arm. Dipper was sure to make note of it, though decided against saying anything.
"Oh god oh god oh god!" Pacifica whimpered, trying to ignore the vertigo-inducing view from the cab. "I can't do this, Dipper! This is the worst!"
"You've got to do this!" He shouted back, smashing a boggle into a pile of dust and white pearly teeth. "I believe in you, babe!"
"...Did you just call me babe?"
He paused before striking another with a discarded fire rake. "J-just get to it."
"Pft, if you call me that more often, I'll do anything." She laughed - though it was clear she was putting on a facade. She stumbled over the rattling footplate, dodging toothy projectile after toothy projectile, struggling to hold her balance, trying to ignore the increasingly irritating whistle rope. Through the gap between the bunker and cabin, she could see the town below them - it was tiny. From the height of the great bridge, every building seemed dizzyingly small. It made her feel really, really ill.
"Protect the source of the burning oblivion!" A voice bellowed from inside the pile of fuel. "The blonde human must be destroyed!"
"Hey! HEY!" Dipper barked - but the creatures had little interest in paying attention to him. They leapt at her, pelting her one after the other, backing her up towards the edge of the footplate.
"Ow! Ow! No, no please, don't! NO!" For the first time in her life, Pacifica begged for something. In this situation, it felt like she was begging for her life . She grabbed the handrails and tried her damnedest to maintain her footing as thud after thud rang out from the horrible beasts slamming against her. The air rushed into her ears furiously, lifting her hair and threatening to tear out her earrings. Her sweaty hands gripped tightly, her bruised, exhausted body beginning to feel weak - her legs feeling like jelly thanks to the sheer panic that was pounding through her.
Was this it? She felt her foot momentarily slip and desperately pulled herself forward to try and save herself from what felt like the inevitable. How high was Wentworth bridge? 400ft? 500ft? She didn't even know.
It'd feel like a long way to fall. That's for sure.
"Pacifica!" The sweaty, frantic, page-flipping teenager shouted, darting towards her.
"Dipper, forget it! Close the door! Close the door!" She yelled, her eyes clenched shut - now streaked with running mascara.
The young investigator's eyes were wide, his face streaked with soot, every bit of his expression overtaken by fear, discomfort and overexertion. He could see the tunnel mouth through the cab's filthy windows and knew she was right - as much as he hated to admit it.
He furrowed his brow, trying to fight the urge to grab Pacifica instead, and rammed his foot - and as much of his body weight - against the firebox lever as hard as he could. The door resisted, its metalwork having expanded with the heat. It screeched, grinded - then slammed shut with a scattering of soot, and officially blocked the path of the vicious little things.
At least Kentucky Fried Dipcifica was off of the menu. But now, the Boggle population was absolutely overtaken with rage. Their glorious, fiery fate was officially off of the menu, and they were beyond furious. While Dipper would largely be wasted energy - after all, they were only really capable of pummeling him to a pulp or scalding him - Pacifica was in a particularly fragile position. They could get rid of her. Once and for all.
They continued brutally, smacking and cracking against her hands, her legs, her stomach - until she simply couldn't maintain her grip. She didn't scream. She simply gasped as she felt herself slip off of the locomotive.
She reached out, futily, trying to grab the handlebars - her pupils turning to pindots as she came to terms with the situation.
The world around her seemed to turn into slow motion as she felt herself fall backwards. She could feel the rush of cold air, the feeling of helplessness, that loss of control or coordination. Her platinum hair trailed behind her, her feet flailing, her-
Her entire body caught in an elaborate cat's cradle of high-grade railroad rope.
Dipper knew that would come in useful. He grinned proudly at his own ingenuity, grabbed the end of the cord and yanked as hard as he could. If there was one thing that Dipper could be damned well sure of, it was that his panic reflexes were his ultimate weapon.
"Oof!" Pacifica fell against him and gripped his vest tightly, both of them desperately trying to catch their breath - which was a hard thing to manage, when there was an 8-ton gang of crazed sedimentary carbon creatures preparing to batter them.
"D-Dipper, you just-"
"L-look, don't say I've s-saved you yet." He stammered, nervously, a trickle of sweat flowing down his ashen face. "We're still travelling god-knows-how-fast in a steam engine we don't know how to drive."
As if to accent his words, the locomotive plunged into the tunnel on the other side of the bridge, drowning them both in darkness without the light of the firebox to illuminate them. They held onto eachother tightly - protectively.
"At least we've got the book for a fighting chance." She whispered.
"We'll need it."
"Dipper, you just caught me in mid-air with a lasso made of a train's whistle rope. I'll believe in anything right now."
"If it's any consolation, I think I saw Quentin flying the giant goose. He'd have caught you."
"Don't ruin this, you dork."
"Stop trying to make an out-of-control train romantic, Paz. We're probably gonna die."
Pacifica scoffed and tapped his nose. "Then there's no better time!"
"How are you so calm?!"
"I just nearly fell off a bridge, Dip. I'm kind of riding an adrenaline wave right now." She retorted. "Now, get reading. I know for a fact you're faster than I am with technical junk."
Dipper wheezed as she shoved the manual against his chest. "Wh-what will you do?"
"I'm gonna make these things regret ever even trying to mess with us." Pacifica grinned as she sliced a Boggle in half with a shovel. "I'm a Northwest. And I was taught to crush my enemies."