"On the horizon to the north is the Irish Sea with Anglesey to the northwest. That milestone you're leaning on is Roman. You see a sunken grassy track here. It links ancient forts."

"There's a hell of a lot of history here, Ryder. Are we witnessing the end game?"

"I've often thought that while strolling around up here, hoping I won't see any strangers. Yet, I get a pang of hope when I see a curl of smoke from a chimney. I certainly didn't expect to see any more airplane trails."

"Sure is peaceful up here. No doubt in contrast to the chaos and mayhem in the coastal cities. We need to put our mind to opening that damn case. It might be the last hope for any of us."

Ryder agreed. "We'll walk along this ridge for a while. I'm looking but can't see any strangers, but you never know who, behind curtains or a bush, might see moving shapes along a skyline. We're hidden for a mile, and then we'd better nip back down into the Anafon Valley and head towards inspecting our security gates."

"We're not going to be scaling Mount Everest on the south side of the centre, are we?"

"Llwtymor Mountain? Not today. There are the remains of Second World War aircraft up there."

"This one little valley is a gem of a place, Ryder, and yet you say hardly anyone rambled over it on a daily basis before ARIA?"

"Gets to you, doesn't it? Especially poignant now. See our new wire fencing between the gaps in the stone wall? It wouldn't keep anyone determined out, but hopefully the signs will deter them."

"Yeah, I wondered about the 'Active Firing Range' notices. Neat."

They kept their heads below the skyline as they hiked west until following an old sheep track back down to the small lane. They soon came to a new gate.

"This is the second gate a vehicle would have to go through to reach our centre. See how there's a rocky bluff from the mountain on this side right down to the road and a steep slope down to the river on the left?"

"I've waved at the camera, Ryder, but is anyone watching?"

"Si there is, Commander," said a tinny voice, from a speaker.

"That you, Antonio? I thought this gatepost had an Italian accent," said Dan. "Keep your hands off my dinner."

"Ah, Dan, I let my hands take what they can, but I'll leave your pasta alone."

Ryder walked up to the microphone. "Is Teresa there?"

"I will seek her out."

Ryder imagined his grinning face.

"No, don't bother. I'll catch up with her later," said Ryder, but Antonio had been replaced by Brian.

"Everything all right at the gate, Ryder?"

"Yes, Brian, see you later." Ryder stood, hands on hips. "How did you keep your hands away from punching Antonio on board the ISS?"

"Never needed to. My wife left me two years ago. If he tried it on with Jena, it wouldn't have bothered me as long as the assignments were on target. Are you unduly worried about him and Teresa?" Dan gave the gate a tug to check how solid it was and noted the razor wire along the top.

Ryder test-kicked the bottom spar. "Logically, we need to adjust our emotions to fit the new situation."

"Easier said than done. Though it looks as if our Jena has the hots for you, or haven't you noticed?"

"Yeah, well. Teresa's hard enough to handle. Could I control Jena? Isn't she making a play for all the new men here at Anafon? Just asking?"

"Nope, I reckon she goes on full broadside for one target at a time. If you want my advice, let her have you."

"What? Dan, that isn't the kind of well-brought-up Godly advice I'd expect from you."

"Hell, it's just practical, Ryder. If you don't, she'll keep on and on. Anyway, she's darn bright and a lot of fun, I guess. Difficult and independent too. Want a hot-water bottle or a wild cat?"

"All this relationship stuff does my head in. Haven't much time for it now, have we? Let's consider the case again."

"Fair enough. The mine is isolated and you have sensors and remote operating facilities to check the case out during its opening."

"You do remember the problem opening the first case by remote handling?" said Ryder.

"If I recall correctly, it wouldn't open until a human got real close. I wonder if it was the warmth-an infrared sensor-or has it a human-contact sensor beyond our technical experience? It would have helped to have had a detailed analysis of the case after it opened. I know the situation became rapidly confused with the breached containment protocol, but before memory loss took over..."

"No, Dan, the memory loss is effective immediately. Within one hour of being in the vicinity of the open case, you'd lose two days of memory. So if his new headache and confusion let him, the techie would think-what case? The Edwards contamination started slower, but the case wasn't opened there. Further infected people don't display memory loss until after sleep."

They continued walking, talking, taking delight in the aromas from the heather, damp soil, and that nostril-widening experience with clean air. Ryder leapt on a waist-high boulder and eyed his binoculars.

"Hey, Dan, I can't see Jena anywhere. Have you?"

"No, I'll try her cell phone. Good job you people have set up a narrow-band local network. Nope, turned off. She must be back at the centre."

Ryder used his own phone. "The centre hasn't seen her either, but Brian said he'd use the cameras, and if necessary, the flying cam on a drone model airplane."

"My God, you are prepared."

"She gave me the impression she wasn't used to off-road biking. Suppose she's had an accident and is unconscious?" Ryder's irritation of her had transformed to concern.

"How much daylight do we have left?" Dan said. "We could split up and go along both sides of the valley."

"It's four, so we have at least two and a half hours. I don't want to lose you too. Stay with me and I'll get Gustav and Brian to nip out while the women operate the remote webcam."

After fifteen minutes with no sighting, Dan, puffed again, said, "Are those paths easier?"

"You're looking at sheep tracks, they'll go anywhere. Hello, I'm getting a call from Megan."

"Hi Dan, it's all right, I caught a glimpse of Jena round the stores area back here at the centre."

"Excellent. Thanks, Megan."

"Hang on there, Megan," said Dan, asking Ryder for the phone. "Did she bring back your bike?"

"I suppose so."

"Megan, do me a huge favour, kid, and look?" asked Dan.

"Cor, I don't know. I'm peeling bloody spuds here. Oh, all right then. It's not far, I suppose. Be right back."

"You are a star, Megan," said Dan, as he and Ryder listened to Megan's objections, Welsh-accent banter and heavy breathing. Ryder raised an eyebrow at Dan but acceded to the commander's more insightful experience of Jena's character.

"Right. I'm where my bike is kept."

"And?" Dan had to drag it out of her.

"She must have put it in the wrong place. Shall I have a look around for it?"

"No, Megan," Dan said. "Get back to your potatoes, but thanks." He turned to Ryder. "There's no point in Megan spending time looking for a bike Jena is still riding. Megan probably did see her. She went back there for I don't know-a drink, her camera, a Band-Aid for a grazed knee?"

"Pity," said Ryder. "I was hoping to call off the search, but I suppose we'd better continue it until someone else spots her and reports an actual live sighting. It makes a worthy exercise, anyway."

"All this hiking is sure giving me a monumental appetite," Dan said. "I hope Megan has-hey, what's that cloud?" He pointed south where a brown cloud grew from the base of Llwtymor Mountain. Before Ryder could react, they both heard a deep, booming crump sound. Ryder trained his binoculars but intervening hilly ground obscured the exact source.

"I have a nasty feeling about this."

"It's from the mine, isn't it?" said Dan, his query punctuated by another rumble and a fresh dust cloud. Ryder's mobile phone bleeped him.

"Ryder, it's Brian, explosion at the mine. The cameras and sensors have blacked out. We're on our way."

"Brian, hang on. Don't enter the mine," shouted Ryder at his phone.

"I'm not bloody stupid, Ryder. I know there could be more collapses."

"It's not just that, Brian. The case. We won't know if it is damaged or what it might release. If you can access the mine entrance, there are bio and space suits in large plastic bags. Let the ISS people have their own custom-made suits and we'll have our bio suits and-"

"Like I said, I'm not stupid-what?"

Bronwyn's voice came across. "He hadn't thought of that, Ryder. Thanks. See you there."

"Good, but I need to know that at least two people are monitoring cameras and comms at the centre-don't all of you go."

Saturday 19 September 2015: Anafon Field Centre.

LARGE BOULDERS OF GREY FINE ROCK NOW PILED AROUND THE MINE'S ENTRANCE. Ryder's heart sank when from a distance, he saw people coming out of the entrance after he'd demanded no one went in. Wisps of smoky dust escaped from the gaping mouth and puffed upwards.

Ryder and Dan ran the last hundred metres. Antonio and Adbul were being helped out of their suits by Vlad and Gustav.

"Taking them off?" Ryder was ready to assert himself.

"Si, sorry to disobey orders, capitano," Antonio said.

"I should expect more resp-" Ryder continued, but Dan touched his elbow to alert him to what lay in the grass by the side of the mine. Megan's bike.

"Did you locate Jena in there?" said Dan to his men.

They shook their heads. Abdul said, "That's why we went in as soon as we were suited up." He looked at both leaders for approval. "But the roof has collapsed about a hundred metres in. Impassable."

"Jena was in there when the roof collapsed, then," said Ryder. "Damn."

"She might be trapped and not crushed," Gustav said. "We should prepare to clear a crawl-space through the rubble."

"I'm glad you said 'prepare,'" Ryder said, "because not only do we need to bring up roof support materials, we need to ensure we are not contaminated by the case."

"I like this man," said Dan, to his crewmen.

"I thought you might. He's as methodical and as slow as you," said Antonio, ducking as Dan threw a handful of gravel at him.

"You can fuss and make plans," said Abdul, refastening the Velcro on his suit. "I will be making a start. No matter what you say." He disappeared into the mine entrance.

"Okay, there are preparations we can do quickly," said Ryder, flipping open his phone. "Brian, get the trolley ready and hitched to our smallest vehicle. Load up some materials suitable for shoring, crowbars, ropes and winch cable, and extra torches. Thanks.

"Antonio, I suppose the overhead lights are out?"

"Blown by the vibration."

"Right, Brian, are you still there? A box of light bulbs too. Okay, Antonio, you might as well get re-suited and follow Abdul. I want people working on a buddy principle. Understand?"

"Si, Ryder, il Duce," said Antonio.

"That's enough, Antonio," said Dan, going over to help him suit up and shut up.

After Brian arrived, they made short work of unloading the equipment and cleared enough rubble to get the trolley in with a winch cable.

Ryder took Brian to one side. "I don't suppose anyone was looking at any of the mine cams when the roof collapsed?"

"Afraid not, and we don't record. Waste of time and resources. I'm concerned about how it happened."

"I'm no expert in mine stability, Brian, but I would've thought that if the mine stayed intact for two hundred years, it wouldn't have collapsed just because we turned it into a furnished let."

"Well, the way I see it, Ryder, all mines collapse sooner or later. You can't just dig a mine and not expect millions of tons of annoyed stone to press down. And why not, when some idiots start drilling and knocking bolts in the walls and ceiling?"

"Dan and I heard two loud noises. I suppose the roof collapse would be noisy, sudden, and create an echo around the valley. Or did you-"

"Ryder, as you know, I was at the centre, only a mile away from the mine. I worked in the quarries years ago. I'd swear I heard an explosion followed by the roof collapse."

"It gives us two possibilities."

Brian's soft Welsh accent belied his words. "Only one from where I'm standing. That cow, Jena Kochi-Chinese isn't she?-blew the case because-"

"Go on, Brian. I'll overlook the racist bigotry for the moment but give me a reason why she'd destroy the case?"

"Everybody knows the Chinese would want the case for themselves. She's probably been in touch with them and followed orders."

"Good grief, you're unbelievable, Brian. Scary."

Brian folded his arms and set his face to withstand criticism with no grace.

"Brian, Jena Kochi has a Canadian mother and lives in the US...with a Japanese father."