Episode 10, "Sacrifice" of "Reign" solidifies the bond between Bash and Mary. King Henry and Francis are missing from this episode, while Queen Catherine plots the death of Bash. Here is a Recap of "Sacrifice":
The episode opens with a sword fight between Bash and one of the guards. The guard out-manoeuvres Bash. He tells Bash to learn to expect the blade that can't be seen. Otherwise, it will be the last thing that he ever learns. Bash introduces the guard to Mary, as his new bodyguard, Alec, sent by his mother. Mary wants to know why Bash is not present in the throne room, as everyone is expecting him to be there. Bash has to show to the noble-men that he can become a capable King of France.
Bash believes that at the throne room, the noble-men are waiting for his fall, as a bastard's succession to the throne threatens their line of succession. Mary convinces him to be at the throne room. There, Bash is bored to death, listening to mundane complaints. He is not too amused listening to chickens and goat feud. When Lord Hugo asks him to resolve the feud, Bash comes-up with some silly ideas. However, he is fully awake when a pregnant, young woman is brought-in. She is accused of stealing. Bash is a little rattled but soon composes himself, ordering girl's home to be searched and incarcerating the girl in the castle.
Once the young girl taken-away, a woman arrives, approving the bastard as the King. She takes some steps forward to meet the King when Alec brings her down. She is holding a small knife, which has been dipped in poison. It was an attempt to kill Bash.
Mary goes to the prison cell where Queen Catherine has been kept. She is enjoying all the comforts of life and the list of people serving her has been multiplying. Mary demands to know if the attempt on Bash's life was on the Queen's orders. Catherine does not deny that, but does not confirm the accusations, as well. There is no evidence against her. Mary orders that everything should be taken away from Catherine's cell, including food, clothes, tapestry and all the amenities. The guards have to oblige, fearing King Henry's wrath.
Mary finds Bash with the young, pregnant woman. She doubts that the girl might be pregnant, with Bash's child. Bash tells Mary that the young woman is his cousin, Isabella, daughter of his mother's half-brother. Isabella is not pregnant with his child but Catherine thinks so. The child's father passed-away in an accident. Isabella's father was accused of treason and as a result, he was beheaded for his crime. If anyone finds a connection between Bash and Isabella, and that a traitor was his uncle, Bash cannot be the King. If the real identity of Isabella's father is discovered, she will be tortured and might reveal her connection to Bash, which is worse than what they doubt -- Bash and Isabella are lovers.
Mary decides to help Bash. Isabella is showing signs of going into labour. Mary and Bash chart-out a plan to fool Catherine's guards and help Isabella escape her condemned fate. Mary accompanies Isabella in a carriage, while Bash takes another route. Before leaving, Mary asks her friends to keep an eye on the Queen and find evidence against her.
Lord Hugo visits the Queen and updates her on the latest developments. He tells her about the plan to trap Bash and Isabella [Queen calls her Bash's whore], together, in the night and then killing them. Queen asks him to come next time, with some food. Lord Hugo says he will return with something better, news of Bash death. Lola, Kenna and Greer are the next to visit her, warning her to stop her plotting against Bash and Mary. Queen Catherine is not the one to back down. She insults the three girls one by one, calling out their weak points.
Bash meets Mary, Isabella and Alec at a spot inside the forest area. Isabella's water has broken, which stops their movement out of the woods to a safe haven for the young woman. They pitch a tent inside the forest area and keep a watch. It is pitch dark outside the tent. When Mary steps out to bring water, she finds a marking of pagan, which alludes to the mark of death. She breaks down a pagan structure. When Bash and Alec learn about what she has done, they are hyper. Mary tells them that pagans would have killed them if she had not done that.
Pagans soon surround the tent, chanting a hymn. Bash, Alec and Isabella hum the same hymn, and soon the pagans leave. They do not leave before beheading a horse. Mary is furious as she believes Bash is a pagan and a heretic, and it is the truth that he was hiding from her. Mary's absolute hate for pagans surfaces. Bash tells her that he is a catholic but knows the hymn because of visiting his uncle's place as a child. Isabella, her father and Alec are pagans, and Isabella's father was beheaded because he found out to be one.
Isabella gives birth to a girl. However, she soon passes away because her bleeding does not stop. Before dying, Isabella asks Bash to take care of her daughter like he took care of her. Bash promises to do so. He gives the baby to a woman, asking her to take proper of the motherless child. Mary notices a mark on one foot's sole. Bash tells her that it is a pagan custom and Isabella must have done that. The mark may disappear.
At the castle, Catherine's taunts and insults give Kenna an idea. Lola visits the Queen with two letters in hands. One has written evidence that she ordered Bash's killing. The letter is fake but enough to start an investigation that might make the guards crumble and reveal Queen's hand. The other letter is of Queen ordering the opening of her gold vault to celebrate Bash as the next King of France. It is in Queen's hands, which letter she wants to release.
Bash and Mary return to the castle, with Isabella's body. Bash tells Lord Hugo he had to kill Isabella because she attacked him. He feigns ignorance about the missing baby. Lord Hugo has no other option but buy that explanation.
On Isabella's mud grave, as per Pagan's custom, Bash cuts his hand and drops blood. Mary follows him and does the same. Bash tells her that if he never wanted the crown, but if that is his fate, he will accept it and learn to wear it. However, Bash says that she needs to know that he is not Francis, and his "duty will never be to some country, some land, or some throne." He adds that if he marries Mary, she will become his family and he will do it for her and only for her.
Mary stops him from saying anything further and kisses him. Bash reciprocates, as well.