Wood Between the Worlds 2 Treasure

We ran to my house, and saw Norman and Billy kneeling next to a hole, dug right next to the old stump in the middle of the yard. They were peering down into the hole. “We see a bag or something but it’s caught on a root,” explained Billy. James took Norman’s shovel, and I took Billy’s.
“Now, understand that this is probably just a bag of rocks or something that someone wanted to get rid of,” I explained to the boys as James and I picked at the bag. “Under a tree?” said Billy.
He had a point.
“And why would somebody bury rocks? I bet they’re hiding something. I bet they’re hiding gold. I bet pirates stole the gold, and hid it under a tree here.” Billy was on a role. Norman seemed to be a pretty quiet kid, but he was nodding as Billy talked.
“Why would anybody hide anything under our boring old tree?” I asked Billy. His eyes went wide. “It hasn’t always been our boring old tree! Maybe it once belonged to a royal family and they had to hide their jewels!”
James interrupted us. “Hey, I got it!” He reached down and pulled out a bag. We all huddled around it as he opened it and pulled out another bag. He peeked in the bag. “It’s just-” he broke off.
“Well?” asked Norman impatiently. He grabbed the bag and reached in. he came up with a handful of what looked like green rings. He tossed one to each of us, and we all put them on. James got another bag, and this had something written on the side of it:
“Please handle these rings with care,” was scrawled in a childlike cursive. “Make sure you have the green ones on your person.” I rolled my eyes. “Open the bag,” I said impatiently.
James reached his hand into the bag- and was gone.
I shrieked, and grabbed Billy’s hands. “Don’t touch whatever is in that bag!”
“Dot!”
“No! It’s not safe!”
Norman sighed and reached for the bag. “I don’t know about you two, but I want my brother back.” He grabbed something from the bag and disappeared as well. Billy glared at me. “We have to go find them now.”
“No, Billy! I’m sure they’ll be fine.”
“I’m not sure! And I want my friend back, and if you don’t come after me I will tell Mom how you don’t look after me, and you’ll be in more trouble that you ever will be wherever they went.”
Billy wrenched his hands out of mine with surprising strength and reached into the bag.
I sighed and peeked into the bag. I had been expecting something horrible, but all I saw were gold rings. I checked to make sure I had my green ring-I did-and slipped a gold ring onto my finger.
All of a sudden I was spinning rapidly away from our house in London, and I watched the city, then the country, and then the world get smaller and smaller.
The next thing I knew, I was emerging from a pool, but I was dry when I crawled out of it. I looked around, and saw James, Norman, and Billy all sitting underneath a nearby tree, looking as if they had just woken up. I saw trees and pools everywhere in this green wood. There was a strip of earth cut away from the pool I had emerged from. I pointed to it. “Did you carve this?” I asked James.
He shook his head. “No, it was there.”
I looked around. “Where are we? Not in England, I watched it sail away.”
He shrugged. “I don’t even think we are in the same universe.”