Reign / 9:00pm (50) A show about European royalty seemed like a big swing for a network largely weaned on dramas about the supernatural and superheroes, but this saga managed to have a healthy four-season run. That ends with the series finale, “All It Cost Her ... ,” in which Mary’s (Adelaide Kane) decision seals not only her own fate but that of her country. Elizabeth (Rachel Skarsten) girds herself for battle, literally, but realizes what she and Mary have in common.
Dark Matter / 9:00pm (Syfy) In the new episode “Welcome to the Revolution,” the Raza gets a distress call from Tabor (David Hewlett), their handler, but when the crew responds, he is nowhere to be seen. Instead, they encounter his former assistant, Adrian (Mishka Thebaud), who awaits them on an outer colony that’s in a tense confrontation with their corporate overlords. Before Six and Two (Roger Cross, Melissa O’Neil) can debate whether to get involved, that decision is taken out of their hands.
The Great British Baking Show / 9:15pm (22) The culinary competition gets its fourth American season, as twelve amateur cooks set out to flour — er, flower — in the kitchen while their skills are assessed by returning judges Mary Berry and Paul Hollywood. The contestants’ first mission will be a piece of “Cake,” literally if not otherwise, as they tackle challenges that incorporate sponge and chocolate elements.
Wynonna Earp / 10:01pm (Syfy) 4:30am (Syfy) A prickly lot even at the best of times, Wynonna (Melanie Scrofano) and her team are finding it very hard to adjust to the new world order in which they find themselves, and the arrival in Purgatory of one of Wynonna’s old friends only complicates those personal dynamics in a new episode called “Shed Your Skin.”
“The Great British Baking Show” airs Friday on PBS.