The explosions aren't stopping.
Daniel barely has the time to curse as he runs over shaking slabs of striped rock that seem on the brink of rupturing under his very feet, but he can hear the rumble and occasional booms quite well.
Except… they don't quite sound like explosions; more like the rumbling tremors of a series of landslides.
What the hell is going on?
"Earthquake!" answers River succinctly, vaulting over a golden-hued crumbling rock.
Daniel automatically follows, throwing himself between two collapsing sides of the cave that seem intent on merging into each other. "Did I say that out loud?"
But now that he thinks on it, she's obviously right. The shaking, the rumbling, the electrical charge in the air, the displacement of the ground and rock walls, it just might be possible that this is-
A portion of the reddish soil vanishes from right before him and he finds himself suddenly without purchase on the ground as it shifts and roils under his very feet, and he's too busy throwing himself aside and then jumping over the crack to complete the thought.
River does it for him.
"This ground is made of soft thick sediments, it's amplifying the shaking. The effects will likely continue for a while even if the seismic event is over. Chances are, we'll be caught in a landslide or a collapse soon."
She really, really shouldn't sound so calm about it.
Daniel stops after a little while and gulps down some much needed air. It feels like it's been ages, but rationally, he knows it mustn't have been more than a minute or two. The worst of it is over, the jolts and rumble died down, but River is right: the area around them is far from settled.
She's eyeing a narrow passage between two orange-tinged rock walls whose sedimentary stripes have been shaken all out of sorts. The result is almost artistic, though Daniel could appreciate it more if they weren't still cracking ominously and about to be crumbling around them.
Assessing the situation, Daniel groans.
The newly created crevasse behind them isn't any better, however, so he resign himself to the umpteenth crazy run-for-his-life of his career.
"Of all the rotten luck..." he grumbles, taking a chance to draw breath before risking a squishy death (again).
"Luck? Ha! This is your friend's fault, mark my word," River corrects him before launching herself through the iron-rich rocks at a run.
Daniel breathes a little more easily when they both make it out on the other side before the orangey rock crumbles, its previously ordered layers all upset.
"How can this be Jack's fault?" he cries. "You can't just make an earthquake! Can you?"
She gives him a dazzling smile: "Oh, earthquakes are rather easy to provoke – I actually have some experience with that."
"You… what?"
"Well, you know how it is – there was this underground cartel managing illegal mines and a ridiculously oblivious panda-like dictator and far too many cyber-guards and really, what it boils down to is that my husband is fond of drastic solutions. But that is neither here nor there."
She's scanning their surroundings with the expertise of a soldier now and slowly relaxing as all shaking and tremors are dying down, but Daniel is kind of stuck on the topic of provoking earthquakes.
"But don't you need, I don't know, nuclear bombs or something for that? Because these people don't have them and we sure as hell didn't bring any!" There is a faint accusatory tone to his voice.
She rolls her eyes: "Have you been watching 20th century superheroes movies?"
Daniel gapes at her.
"Nuclear bombs are useless for provoking earthquakes," she lectures primly. "Also, far too messy. All those horrible side-effects. No, all you need is a dam."
"There aren't any dams on this continent."
"Or," she continues with a mild glare, "a sufficient mass being slung around." She starts walking. "Truly, if you want to make an earthquake, forced shifting is far more effective than delivering a momentary blast – sling enough mass around to alter the pattern of stresses in the planet's crust and faults that might have been stable for a million years can suddenly be pushed to failure."
"Still doesn't mean it's Jack's fault," protests Daniel, who isn't in the mood for this particular lesson right now.
"I highly doubt anyone else might have caused this. I imagine he was trying to create a diversion in order to rescue you and your friends and things rather got out of his hands..."
"I can't believe anything Jack might do could be enough to cause… this!" he cries, almost offended, while gesturing at the devastation around them.
"I could go into details about the transfer modes of seismic motion in relation to the geometrical setting of deep and surface deposits, and how local amplification can result in high levels of shaking on the ground even from low-intensity earthquakes, but something tells me you wouldn't be too interested," says River sardonically.
Daniel shoots her a half-hearted glare.
The ground under their feet trembles and plunges abruptly in a ravine. Swept up by the landslide, they cannot keep their balance and are thrust rather violently against the nearest rock wall – where, at least, they find enough of a hold to drag themselves out of the worst of the flow.
Daniel hugs the wall, closing his eyes and sort-of praying. He's quite grateful that his glasses are still on his nose.
When the last rumble of the landslide quiets, he opens his eyes and then closes them again with a wince. They're precariously balanced on the narrow strip of rock that wasn't dragged down in the tumble.
River doesn't seem fazed in the least – in fact, she's checking herself in a hand-mirror – so Daniel forces himself to sound nonchalant.
"Well, what do we do?"
"Do?" she raises an eyebrow at him and snaps the hand-mirror closed before walking confidently off onto the barely-there pathway. "We're escaping, what else do you want?"
Daniel can't believe his ears: "But… but… the Caves! We can't- all that history! How do we stop this?"
She sighs – long-suffering and bored. "These Caves were lost! Nothing of them remained. Didn't I tell you when we met?"
Daniel gapes at her in horror: "We can't let that happen!"
She looks at him with pity. "It has already happened!"
Time travel, Daniel realizes, can give him a headache even if he doesn't think of it.
They're moving along the far too narrow ledge now, sliding slowly over the barely protruding rock. Daniel is trying every calming technique he's ever heard of, from any culture, in an attempt to forget the plunging abyss under their feet.
River moves confidently, her grace unimpaired by the lack of purchase for her feet. She jumps lightly over a gap in the rocky ledge.
"Will you be careful!" hisses Daniel, feeling his heart in his throat.
"Careful! Bah. Tried that once. Ever so dull," River replies airily.
Not ten steps later, the ledge they're on collapses (as Daniel had suspected it would all along) and they're swept away with a landslide again, though thankfully the plunge is shorter this time and in the end, they tumble to soft ground.
"Ouch."
Bless muddy, grassy soils everywhere, thinks Daniel.
River is up and about sooner than his bruised limbs would like, but Daniel doesn't complain out loud.
He's too busy worrying about the smallish village that has been devastated by the landslide, the cries and screams that feebly reach them even at a distance. There aren't many people, but none is uninjured and at a glance, he cannot find a single rigid structure still intact.
Without even realizing it, he's babbling aloud about first aid and damage assessment and what he can and cannot do and does River have any experience with this kind of things?
"No time. I doubt the locals are taking all this well, your friends are almost certainly in grave danger," she rebukes him.
"But we have to help!"
"Yes, we do. It's what I just said."
"No, I mean that village!" Everything in him is rebelling against abandoning them to their own devices.
"It really kills you when you can't make a difference, doesn't it?" wonders River aloud. She smiles sadly. "No wonder my husband spoke so highly of you."
"Do I know your husband?"
"Oh, that's really too complicated a question to bother answering," is the baffling reply. "Do you still have the quairwax?" she goes on before he can ask… anything, really.
He blinks, then pats his pocket reassuringly.
"Let's go then."