We headed back west, into forest on the lee of Three-Fingered Jack. The road was tough for the Civic. I kept stealing looks at the bagged toad in the guide’s lap. Finally, he signaled a stop at no place in particular. “Do you have any flashlights?”

I told him I did. There was one on my phone, and I took one from the glove box and gave it to Alyx.

As we got out, I noticed a four-inch pit in the dust. Alyx had never heard of antlions. I caught an ant and tried to demonstrate. I kept dropping the ant in the pit, but the antlion wasn’t hungry, so I dug him up to show her. Alyx was impressed and a little repulsed as it humped across my palm.

The guide started off without us, toad bag swinging in his grip, and we had to catch up. We passed from pine-needle duff to bracken and into a fir grove that was incongruous among the old pines. The air became cool, and strangely thick. I got light-headed. It was very odd.

“Lots of oxygen here,” said the guide. “They need it to grow so big. Usually, they mindfog people wandering in, to redirect them, but they know me.”

We paused after a climb, and Alyx sat on a rock. She noticed it had a deep cleft.

The guide said, “It’s the top of an old fumarole. Watch this.” He set down the toad and brought out a box of matches. He lit one and tossed it in, standing back. The match wood erupted into a ball of flame. He waved us forward, and we watched the ball flare brighter as it dropped down, down into the deep dark, throwing sparks before it died.

“This is where the oxygen comes from,” he said. He retrieved his toad. A little further on, we approached a larger hole in the ground. “I set a ladder here,” he said.