Season 4 Episode 16 All it Cost Her… (Series Finale)

Reign Season 4 Episode 16 "All It Cost Her" Promo (Series Finale)

Reign Season 4 Episode 16 "All It Cost Her" Promo (Series Finale)

In the series finale, Mary changes the course of history with a decision she makes, and her perilous move for survival causes her to have a stunning realization in Reign Season 4 Episode 16 "All It Cost Her" airing next week on The CW.

Watch the first promo below! 

Looking for more spoilers? 

Head over to Reign Episode Guide: “All It Cost Her” for the full description of this episode.