Historian Alison Sage has made a groundbreaking archival discovery --- she found a manuscript containing the prophecies of a 16th-century nun, Elizabeth Barton. Barton’s prophecy condemning Henry VIII and Anne Boleyn led to her execution and the destruction of all copies of her prophecies --- or so the world believed. With Alison’s discovery, she is catapulted to academic superstardom and scores an invitation to the exclusive Codex Consortium, a week of research among a select handful of fellow historians at a crumbling manor in England. What begins as a promising conference turns into a nightmare as the eerie house becomes the site of a murder. Suddenly, everyone is a suspect. Alison’s research makes her best-suited to solve the mystery --- but when old feelings resurface for a former colleague, and the stakes of the search skyrocket, everyone's motives become murky.