My wife and I had already completed our list of the more typical adventures: Bungee jumping, white-water rafting, skydiving, mountain climbing, even diving with Great White sharks. But, with each new adventure, the adrenalin rush seemed a little less intense. So, when we got to the Hawaii Volcanoes National Park for our latest adventure vacation, I thought I had to do something to ratchet up the excitement. My brilliant idea was to explore one of the newest and freshest caves on the planet: A new lava tube.

The trouble with a lava tube is that it’s not like an ordinary cave. Those are usually cold and damp. Lava tubes are hot—really hot. After all, they are formed as hot lava forces its way through older and cooler lava, called basalt, leaving a nearly perfect tube. Even the old dead ones never seem to cool down.

While it was physically impossible to enter a truly fresh lava tube, I figured we could explore a recently cooled one in an active field. Even a cooled tube could fill again with lava at any moment, making the danger and the excitement greater than ever. All we had to do was keep from being incinerated.

We also needed to con one of the park guides into finding us a good tube and guiding us through it. We found our victim—I mean guide—Michael, during our initial tour. At first, he laughed at the idea. Then, when he realized we were serious, he looked frightened. A generous cash advance procured his cooperation. Volcanologists don’t get paid much.

Three hours later, it was just the three of us a hundred yards or so into a tube and Michael looked more nervous with every step. The air inside the tube shimmered with heat in the light of our helmet lamps. It was becoming impossible to breath and I was getting dizzy. There was a constant rumble from a distant eruption, which seemed to be getting louder. Maybe it was just the heat pounding in my head.

As I lowered my head to gain my composure, My light caught an object on the cave floor. It was a geologist’s rock hammer, its point driven deeply into the rock.

“Michael, is this yours?” I called,

“Is what mine?” Michael gasped.

“This hammer, here,” I replied, pointing to the hot basalt at my feet.

“No, mine’s still on my belt,” he replied, putting his hand on his waist.

“Well, it’s not mine, either.” I said.

“Or mine!” said my wife. Her voice was weak and thready and the look on her face told me that this adventure was no longer thrilling.

“Someone else must be in this tube!” shouted Michael. “But I don’t understand. I thought I was the only one who knew about this place! I never even told my grad students about it. At least I don’t remember telling them.”

The sudden panic helped clear my head and gave me my first taste of adrenaline.

“Do you think the owner of the hammer must still be here in the cave somewhere?” asked my wife, her thrill quickly turning to dread.

“I don’t know, but we can’t stay here any longer to find out. And it’s a tube, not a cave! We’ve got to get out. Now!”

“But, we haven’t gone far enough yet,” I protested. “And, we need to find whoever left this,” I said giving the stuck hammer a tug and staggering back as it released from the rock floor with almost no effort.

“You see! This place is going to melt down any minute now! Let’s go!”

Michael was right. The lava tube was even hotter than before and the distant rumbling had turned to nearby thunder. As we stood there arguing, smoke began to rise from the floor. It was definitely time to go. We ran for it.

We reached fresh air and daylight with fresh lava glowing in the tube behind us and Michael’s grad students standing before us.

“Thanks for fetching my hammer,” said one young man. “But, you really didn’t need to.”