On our recent tramping trip to Mt Somers, my daughter and I whiled away the evening setting writing challenges. We chose three words at random from magazines in the hut, and used them in a story. The words that inspired this story: rhyolite, biodiversity, and me.

We hiked to the summit and set up our camp on a windy knob. I would have preferred to camp lower down, but the wētā we were studying lived in the cracks on the rhyolite cliffs just below the summit. We would rappel down from the top, our collecting jars in a sack attached to our harnesses, to gather our subjects.

“Caroline, you go first,” said Mark.

“Me?” I had hoped to watch one of the more experienced climbers descend first. I didn’t want to show the others how nervous I was about it though, so I stepped into my harness and tightened it.

At the brink I paused to make sure everything was ready. I knew if I glanced down even once I’d chicken out, so I kept my eyes on the rock in front of me as I slowly made my way down. I focused on admiring the beautiful, angular columns, the reddish colour. I looked for likely wētā hiding spots. I glanced up and saw Sophie coming down a second rope to my left.

I stopped at a small crevice and fumbled in my bag for a collecting jar and the bent wire ‘wētā tickler’ we all carried to nudge wētā out of their lairs. Focused on the insects, I forgot my fear, forgot the dizzying drop below. I fished out two wētā, then lowered myself a few more metres.

The rock was different here. Less columnar, more green than red. Did the wētā only live in the rhyolite? I didn’t know. I was curious to find out. I probed a near-circular hole in the rock with my wire.

The rock seemed to shiver.

I froze. Was that an earthquake? We’d never talked about what to do if we were on the cliffs during a tremor. All my fear of heights came rushing back.

I waited for a minute, eyes shut. Nothing happened. I opened my eyes and looked up at Sophie. She was poking intently at a crevice, as though nothing had happened. I took a deep breath to calm my nerves. Funny what your imagination can do. I laughed at myself and took a moment to relax my taut muscles and clenched fists.

Calm again, I poked my wire into the hole once more—it was the perfect size for a wētā.

There was no mistaking it this time. The rock moved. I yelped and pulled back my hand as a large yellow eye snapped open in the rock face to my right. There was a rumble, and suddenly a huge head detached itself from the cliff face in front of me. A huge, reptilian head. It snorted, and a wisp of smoke curled up out of its nostril—the hole I had probed for wētā.

Too startled and frightened even to scream, my mind lit on one thought: the biodiversity of Mt. Somers was greater than anyone had ever guessed. And unusual insects weren’t the most interesting things up here.

I wondered if we would make it home to tell anyone.