I took an empty box and buried it under some trees in the backyard.
I told you about my secret box and gave you the key. I asked you to find it, and fill it with treasures so that when a hundred years from now a passing wanderer discovered it, she would see how much you loved me.
And so, a hundred years from now, a little girl playing on the swing tied to the branches of an old oak noticed a steel edge sticking out from under the ground.
She got down on her hands and knees, and dug away at the tightly packed soil, finally discovering a rusted box.
She took a stone, broke the lock.
And opened the lid to an empty box.