Question

And ye, unhappy parents of us both, deny us not our united request. As love and death have joined us, let one tomb contain us. And thou, tree, retain the marks of slaughter. Let thy berries still serve for memorials of our blood." So saying she plunged the sword into her breast. Her parents ratified her wish, the gods also ratified it. The two bodies were buried in one sepulchre, and the tree ever after brought forth purple berries, as it does to this day. How does this conclusion of the story develop the theme of this text?