All their gear was gone

"What the fuck?" I said, darting to my feet, pupils dancing around in confusion. Where I had set my bag and tent now laid nothing but sand and a few tracks, which led to the brush of the forest. I followed the tracks to the edge of the woodland, when I dripped on the root of a tree which had been poking out of the ground. I tumbled down for a solid 20 seconds, before I noticed I was in a small hidden grotto, fit with a pond and a redwood tree, around 10 meters in diameter, which seemed to be hollow in the center, which I inferred by a small opening near the base.

I recollected myself, standing up on my feet, when I noticed a Pokemon I've never seen.