The story I'm currently working on involves a young woman who finds a ancient stone attached to a necklace, and after she unwittingly puts it on she finds herself dragged into a three-way war for its retrieval. My issue is, the beginning of my story is a little dull. It mostly involves my main character sitting on the edge of a pier wondering if she should kill herself when said ancient stone falls out of the sky and into the water in front of her. It works for the story as a whole, but I worry that readers will find it cheap that a story shifts from teenage angst to epic fantasy after said fantastical stone literally falls out of the sky. To amend this, I wanted to have the first chapter of my story be a brief flash-forward of an event that happens much later in the story. Notably, the protag's house is destroyed, her brother is killed and she just committed her first murder after someone she long thought to be her friend betrays her. The flash forward would begin right after said murder occurred, with the previous details being filled in, and would end with her realizing that she can't trust anyone and she must never let anyone have her necklace. I thought introducing the importance of the necklace, alongside the tragedies that its presence inflicts, would help keep the reader interested. I also thought that the inclusion of some small details (the protag kills her friend with a blue-bladed sword) that are quickly answered towards the beginning (the blue-bladed sword belongs to the primary antagonist, how she actually gets it is revealed later) will help show that I'm not just being lazy about this. So for the tl;dr version, how do you guys feel about starting stories off with flash forwards? And if you find them okay, what are some pointers on how to do them properly?