Sam and Jade spent many days together, Jade teaching Sam about the world of rocks they were in, and Sam teaching Jade about nature in the world above. They wandered down the river, talking and learning for about ten days. At the end of the ten days, they came upon and end to the subterranean tunnel. They climbed out into the sun and looked at each other, excitement in their eyes. Endless rolling hills covered the landscape before them, occasionally dotted with tall, straight trees.
Jade and Sam laughed and rolled through the green grass, running and playing together. They spent their days contentedly in the hills, and lived together until the end of their time.

One day, on the side of a hill, a traveler stumbled across two people laying side by side. Their skin was pale, but their faces looked happy and content. The traveler dug them small graves and buried them, then went on his way, not giving the two people another thought.
And in his den, back in the forest, Wolf smiled. Then he laid down his head, and died.

"It was some time before Sam managed to find the cave. He went inside, and searched all over. But he could not find the box. All he found was two small pools.
"Maybe the box is at the bottom of one of the pools," Sam thought.
Cautiously, he stepped into the one on the right. He soon realized that it was little more than a puddle, and got out. When he did he found himself to be a year younger.
Sam stepped into the other pool and immediately began sinking. He began to panic, but could not get out. He simply kept sinking. Just when he thought his lungs would burst, he emerged and was dumped into a river. He spluttered a bit and fought his way to the shore. When he got out of the water, he found he was two years older than when he had gotten in.
Sam looked up an saw that he had come through a little waterfall that drained out of his cave. In the distance he could see other caves with their own waterfalls draining into the same river.
Sam walked for a little while, calling "Hello? Is anyone there?"
After a couple minutes, he heard a voice answer back. "I'm here." It was a girl's voice. Sam followed it until he found its owner. It wad a pretty little girl, about his age. "What's your name?" she asked.
"Sam."
"I'm Jade."
And so Sam met Jade, and forgot all about the box

There was once a young boy named Samuel Kettleson. Everyone liked little Sam. He was always polite, and never talked too much. He was kind to animals, and he especially liked puppies. In fact he reminded many people of a puppy. Happily content with life, unworried, and obedient (if a bit excited).
Little Sam lived in a small village, just on the edge of a forest. The forest was full of every kind of thing. Tall, majestic trees, and miniature mushrooms that made wonderful snacks. It even had animals: everything from the Ruler Wolf to the Servant Ant. Sam loved each and every one of these animals, and spent many days in the forest, talking to them and running with them and playing with them. The animals loved Sam too, especially Ant and Wolf.
One day, Ruler Wolf called Sam to his den.
"What is it, Wolf?" asked Sam.
"I need you to do a favor for me. I am getting too old and weak to rule the forest much longer-" Wolf was cut off by an outburst from Sam.
"What do you mean? Why can't you rule anymore? Where are you going?"
Wolf answered in a mellow voice. "Sam, I am dying."
This brought tears to Sam's eyes. "No, Wolf! You can't die! I won't let you!" Sam buried his face in Wolf's thick black coat and began sobbing.
"There, now, Sam," Wolf said, in a gentle, soothing voice. "All animals will die someday."
"That doesn't mean you have to, Wolf. I love you!" Sam's voice was muffled by Wolf's coat, and he spoke in between sobs.
"Sam. Listen to me. You need to take your mind off of me now," Wolf commanded. "I still need a favor from you."
"Yes?" asked Sam, weakly.
"On the other side of the forest, there is a cave. Inside this cave, there is a small box of wood. I want you to find this box, and bring it to me. It is important that I have it before I die, so I can pass it on to my successor personally. Will you do this?."
"Yes." Sam still sounded a little distraught.
"Good." With one final nuzzle, Wolf sent Sam on his way. "Now, off with you."
"Bye, Wolf." Sam paused only once, at the entrance to Wolf's den. Then, he started off.

It just needs some switches to get before you can win.