The CW has released an official description for the December 12 episode of Reign, which is called “Fated.”

MARY LEARNS THAT SOMEONE CLOSE TO HER WILL DIE — Nostradamus (Rossif Sutherland) tells Mary (Adelaide Kane) of his prophecy that one among them will die soon, which causes Mary to make a decision that will forever change her relationship with Francis (Toby Regbo). Clarissa (guest star Katie Boland) becomes bolder with her endeavors, while Kenna (Caitlin Stasey) informs Catherine (Megan Follows) of Diane’s (guest star Anna Walton) plan for Bash (Torrance Coombs), which ends up backfiring. Alan Van Sprang, Jenessa Grant, Anna Popplewell and Celina Sinden also star. Fred Gerber directed the episode written by Laurie McCarthy (#108).
The CW has also released some preview images from “Fated,” so if you missed them before, here they are again: