The shelf, though, was a precarious perch, only a few inches wide and crumbling in an ever-increasing number of spots beneath their feet. But it did lead to a way out. Possibly.
Kali's reasoning that there had to have been an original entrance to the dome had, in their time of need, led her to seek it out as an escape route and, while successful in doing so, the tunnel she had found was blocked as she'd suspected it might be, manifesting itself now as a vague tracery of rocks beyond the remains of a long-collapsed stone bridge, some of the component parts of which had been visible as tiny islands in the lava before they had been consumed by the bubbling mire. Kali wasn't sure that the tunnel behind the tracery of rock was going to be passable and the only way she could find out was by removing the rocks from the tunnel mouth. The problem was, she had to do it very, very slowly and very, very carefully, otherwise the resultant rockslide would sweep them both into the hottest — and last — bath of their lives.
"You have to think of it like a jigsaw," she said slowly and quietly to Slowhand. She gently removed a rock with an archaeologist's hands, dropping it into the burgeoning lava with a plop. "Each piece dependent on the other to construct — or, in this case, deconstruct — the whole picture without forcing any one piece."
"Really?" Slowhand said, nodding, his arms folded tightly against his chest. He would have smiled at the way her tongue stuck out between her lips as she worked, other than for the fact the lava had reached the soles of his boots and they had begun to sizzle slightly. "Is this an easy jigsaw?"
"Urrm… somewhere between medium and challenging?"
"Right. Like a bowl of fruit with a binyano, an apple and a pear?"
"I guess so," Kali said. She removed another rock and dropped it away, freezing as the collapsed rocks left behind in the fall settled slightly. "If they've all been tipped on the floor and trampled by a betwattled cyclops."
"Fine. You are good at jigsaws aren't you?"
Kali's hand hovered over another rock before changing her mind and extracting the one next to it. Again, she dropped it away. "Nope. Never could stand the things."
"Oh, that's great. Hooper, look, how about that one there? No, that one. That one looks — "
"Will you stop waving your hands about and stand still?"
Slowhand hopped from foot to foot, his soles sticking and stringing whenever they made contact with the rock.
"Getting — a — little — difficult — to — do — that. Could you please get a move on?"
"I'm trying, all right!" Kali snapped. The sweat running off her now had as much to do with pressure as the heat of the lava. She bent and dropped a heavier rock, regretting snapping when Slowhand took the opportunity to wipe her brow.
"Just one more…" she said through clenched teeth. "Easy… easy…"
There was a sudden shift in the rockface, and then a low rumble, and Kali spun herself away from the front of the fall to flatten herself against the wall to its left. Slowhand needed no urging to do the same and, at the very second he spun to the right, the whole pile of rubble collapsed away from the tunnel mouth, avalanching down into the rising lake.
Behind the fall, the tunnel was clear.
"Go, go, go!" Kali shouted, and just in time. The sudden and dramatic fall of rocks into the lava had disturbed its recently calm rise and it began again to spurt and belch. Unnoticed by Slowhand as he darted into the shadowy tunnel mouth, a patch of the molten fire spattered onto his trouser leg, burning into the cloth, but before it could reach his skin Kali followed him in and tore the offending patch away.
"Don't get excited," she said. "That's all that's coming off."
"Hey, flesh happens," Slowhand retorted, and stared at her heavily perspiring form. "Hot stuff."
Kali shook her head — the man could never resist. She followed him into the dark, making out a winding tunnel that curved away into the rock. She hesitated to think when last it had been used, but for a second thought that she caught a stale whiff of whatever had been the last thing to tread the passage, something overtly male — the smell, perhaps, of dwarf? Her eyes adjusted further to the dark and all her instincts cried out for the time to examine her surroundings — especially as she could now see this was no mere cave but a constructed tunnel complete with those X-shaped dwarven runics — but that was simply not to be. The avalanche that had stirred the lava back into angry life had, it seemed, disturbed more than just the lake, perhaps ruptured another vent beneath the dome and, as she watched, the lava began to bubble into and then sweep with increasing acceleration up the tunnel behind them.
"Hooper," Slowhand said. "I strongly suggest that we run."
"Ohhh, running as we speak," Kali said, passing him.
Slowhand put on his own spurt and the two of them raced up the tunnel as fast as they could, but the collapsed rock at the dome entrance was not the only place where the integrity of their dark confines had been compromised, and every few feet or so they found their progress slowed by roof-falls which they had to clamber over. Thankfully, these same roof-falls acted also as makeshift dams — albeit briefly as it didn't take long for the lava to engulf them — and they managed to stay ahead of the flow. Just.
"Hooper, how far to the exit?" Slowhand asked, vaulting over another blockage in front of them.
Kali leapt in his wake, a spray of pebbles from her heel vanishing into the lava that was now immediately behind her. She slammed a palm onto the wall. "Not sure. But the temperature of the rock suggests we've still a way to go — maybe a tenth of a league?"
"Pits of Kerberos — a tenth of a league?"
"Excuse me! You did ask."
"I know but, hells, Hooper, sometimes I wish you didn't know as much as you do."
Kali stopped, slammed her hands on her hips and nodded back where they'd come from. "I got us out of there, didn't I?"
Slowhand sighed and grabbed her as the lava plopped over where they had vaulted, catching up with her heels. They ran on. "Maybe," he said, nodding ahead, though Kali was still so busied staring daggers at him that she hadn't noticed what he had.
"Fark."
"What?"
"The tunnel dips. Deeply. Some kind of U-bend."
"What?" Kali said again. "Why in the hells would it do that?"
Slowhand pointed towards the roof of the tunnel. "Maybe because of that."
Still moving, Kali looked up, then skidded to a halt. A few yards in front of them, the roof of the tunnel nosed downwards and changed in texture, no longer composed of rock but something else, some kind of fossilised remains, a dark and chitinous substance that reminded her of the brackan in the Sardenne. But these remains were not those of any brackan, because they were bigger — much, much bigger — and as well as nosing down they folded themselves through the walls on either side of the tunnel and into its floor, immortalised as an organic archway in the rock.
"The speed of this stuff, we'll never make it out the other side," Slowhand said.
Kali studied the dip, saw that the tunnel levelled out again beyond it and then turned her eyes on the fossil. These remains had to be hardy, considering it was clear to her that the dwarves had had no choice but to tunnel under them rather than through.
"Help me," she said, picking up a rock.
"Throwing stones at the lava won't make it go away."
"The fossil!" Kali shouted. "There, where it's been cracked by the tunnel subsidence! We can bring that part down!"