Reign 4×15 “Blood in the Water” Season 4 Episode 15 Promo – MARY’S LIFE HANGS IN THE BALANCE – Childbirth threatens to take Mary’s (Adelaide Kane) life, which leaves her and her unborn child’s safety in jeopardy. Elizabeth (Rachel Skarsten) discovers that someone in her inner circle was the cause of the death of someone close to her. Dan Jeannotte, Jonathan Goad, Celina Sinden, Megan Follows, Craig Parker, Ben Geurens, Rose Williams, Will Kemp and Spencer MacPherson also star. Charles Biname directed the episode written by Drew Lindo and Wendy Riss Gatsiounis (#415). Original airdate 6/9/2017.