Sia Stevens is a Seattle engineer and relationship educator. A breakup she couldn't explain sent her looking for the root cause of love itself; the year-long search became What Happened to Us: A Fable of Modern Love, her first novel. Its framework — attraction, reciprocation, co-creation — is laid out in full in her self-help book, A Million Green Flags, and taught in her course, Modern Relationships 101. She publishes under her imprint, Vessel & Ink Press, and lives in Seattle.