He left, and she started shoving tools into a damp, and slightly stiff tool belt she'd found wedged between the back of the furnace and the wall. She didn't like it nearly as much as her apron, but she wasn't about to waste the time it would take her to climb back up, one handed, to grab it. Besides, the tool belt was bigger, and didn't have to be tied around her waist. She looped it over her head and wriggled up it rested low on her hips, half her mind now wandering as she tried to figure out whether she could combine the tool belt with the apron -- for posterity's sake. 

Meanwhile, Jötz had made his way into the dark, and the rest of her mind was occupied with trying to make up the last few days to him. She still hadn't [i]quite[/i] gotten over the whole amputation thing, but she could no longer deny he'd saved her life almost more times than she could count now. And he'd lost his hat in the process. She was certain speeding them ahead to the next town, especially along the safety of the subterranean canals, would make him feel a little better, if only so he could go on his way again, hat-stealing, and village-plundering. She supposed maybe she would sort of miss him, but then she'd probably be too busy...doing whatever unfettered Sparks did to care. 

In any case, fixing the engine was something to occupy her time while he sulked and she gave him some space. And she was just beginning to make out the vague shape of a few piston-looking things in the dark, which was [i]great[/i] because she'd [i]just[/i] been thinking about how much better the ÜberOven would have run it if had had a second combustion engine. Of course, that one had run on blueberries, and that just didn't seem practical here. 

Ivy was all about practicality. 

She set the still-ticking lantern beside her for light and wriggled beneath the engine, suspended on to heavy steel pipes she suspected ran coolant through the system, smearing grease across her face and clothing as she did. For a time, and she couldn't say how much, she lost herself in a haze of equal parts curiosity and frustration, muttering numbers, curses, and questions under her breath as she did so. Jötz had probably been shouting her name before several minutes before she heard him. 

"...six-four-seven...could put a pulley in here, and then...nine-one-eight...no...dammit! Why would anyone even [i]use[/i] less than sixteen pistons...five-three-zero...for -- Oh, for Pete's sake, [i]will you shut [b]UP[/b]?![/i]" Ivy sat up in a huff, furious and red-faced...until her forehead collided with one of the suspension pipes, leaving a red welt marked by a black streak of grease straight across her forehead. 

The girl made a face, rubbing her nose with her good hand. "Owwwww," she muttered to herself, squinting through the darkness at the long approaching Jötz. "What're you yelling about?" she started, before her gaze drifted to her lantern, now ticking much faster and smelling faintly of smoke. And mint. Always mint. 

Her face brightened at once. 

"Oh!" she exclaimed, grinning at Jötz as though she'd just discovered the secret to all the world's mysteries. "Look, we can just blow it up and start over! You have to catch any flying parts, okay?" she added seriously. "Your hands are bigger than mine." She reached back under the pipes and gears and springs and switches and snagged the lantern-turned-ticking-time-bomb, and then casually launched it at what remained of the ancient engine.