Third Flatiron Anthologies presents "Keystone Chronicles," 19 fresh science fiction and fantasy stories exploring the theme of keystone events. What is a keystone? It's the central stone at the summit of an arch, locking the whole together, something on which other things depend for support, the heart or core of something, the crux. In storytelling, it is the pivotal message or character who makes it all happen. The international group of contributors to "Keystone Chronicles" make this a unique and varied collection that is sure to please fans of speculative fiction.