Chapter 36

Mauna Loa, Hawai‘i

Time to eruption: 73 hours

Afew hundred yards from the rim, Mac, Jenny, Iona, and Rick got out of the jeep. As soon as they stepped out, they felt the full force of the heat coming down the mountain at them. It was like an oven door had been flung open.

"I thought we were moving closer to heaven," Rick said. "Not hell." Rick fixed his eyes on the summit. "You said Big Mauna was sending a message," he said to Mac. "And I know what it is: You people get the hell off my island."

They could hear the roar from inside the caldera. The earth suddenly shook with a harmonic tremor. Sometimes it was called a volcanic scream; it felt like the hum of a giant bass. They all held on to the jeep to keep from falling, and for a fleeting moment Mac worried that the jeep might tip over.

But the tremor passed.

"I thought I'd be used to the quakes by now," Jenny said.

"Trust me," Mac said. "You never get used to them."

"To repeat the question Sergeant Iona asked a little while ago: Is this a good idea?"

"We're fine," Mac said, trying to sound more confident than he felt.

"Fine?" Rick said. "Check it out." He pointed down at the wheels of the jeep at the same moment Mac smelled the burning rubber.

They all looked down and saw the wheels beginning to melt.

"Everybody, wait here," Mac said. He jumped behind the wheel, gunned the engine, made a hard right turn, and, tires skidding as they spit up lava rock and dirt, drove the jeep back down the mountain.

He stopped at least a quarter of a mile below where he'd parked before, then ran hard toward them, leaning forward to take some of the steepness out of his climb.

"He acts like this is some kind of triathlon," Jenny said to Rick.

"What's next, a swim in the lava?" Rick asked.

"You guys ready?" Mac said when he was back with them, not even out of breath.

"Oh, hell no," Rick said.

The heat became more intense the closer they got to the rim, as did the noise. Even Mac had never heard this part of the mountain so loud—it was as if the caldera had come to a full boil. They all had to shout to be heard above the din.

The heat became more suffocating as they made their way up through the rocks and brush. But Mac knew they needed to do this and do it now. The reality was that they were fast running out of time. Rick and Kenny and the rest of them could do all the projections they wanted about the rate of the rising magma. But John MacGregor was here because of what he considered the cardinal rule of his job: You had to be there.

They kept making their way through the rough terrain, the soil rich with iron and magnesium, the once green crystals of olivine transformed into the orange mineral known as iddingsite. Most of the basalt rocks from previous eruptions were dark gray, sometimes black; some were a brighter rust color.

The closer they got to the rim, the more Mac wanted to stop and look around at this area so near the summit of the volcanic mountain that took up nearly half this island. He was overwhelmed as he always was by the thought of that, and by the reality of nature's beauty, and its potential fury.

But the big clock kept counting down.

Mauna Loa had two rift zones, on its northeast and southwest. Their group was on the northeast side today. There was no more conversation as they made their way the last fifty yards or so to the rim. The roar from the caldera had built up even more, and the sky had darkened somewhat, clouds lower than the top of Mauna Loa.

"I've never heard it like this!" Jenny had to shout even though she was inches from Mac's ear.

He was about to tell her that neither had he when he suddenly felt like his feet were on fire.

He looked down at his hiking boots and saw the thick soles with their wide treads were beginning to curl up and melt away, the way the tires of the jeep had a few minutes ago.

Mac saw Jenny and Rick and Iona staring down at their own boots, which were detaching at the soles.

"That's it!" Iona yelled. "I'll see you guys back at the jeep." He stared hard at Mac. "You want to tell my bosses I deserted, go right ahead."

He started back down the mountain.

"When the going gets tough," Mac said as he watched him go.

"The tough really do get going," Jenny said.

"Just curious, Mac. Are we still fine?" Rick Ozaki asked, furiously stamping his feet on the ground and extracting from his pocket a roll of duct tape to repair his boots.

Mac shrugged. "We've come this far."

Then the three of them were looking down at a lava lake, the heat shimmering off the silver surface.

"This lake… it's new, right?" Jenny yelled to Mac.

Mac nodded. The opening of a new lava lake near the northeast summit confirmed that the lava would head in the direction of Mauna Kea and the Military Reserve.

On the other side of the lake, small amounts of lava were pushing through cracks, and tiny geysers shot lava toward the sky.

"If I could still breathe," Jenny said, "this might actually take my breath away."

"Mac," Rick yelled, "we need to get out of here or we're going to be walking barefoot on hot coals back to the jeep."

"Gimme one more minute," Mac said, taking out his cell phone. "I need to take some pictures."

"For what?" Rick said. "The top of your casket?"

Then he watched as Mac scrambled up and over the rim.