The Winchester hunters solve another "Monster of the Week" case in "Supernatural" season 10 episode 16 titled "Paint It Black." The latest episode of the CW TV series focused on a vengeful spirit that makes people either commit suicide or murder through possession, the Rowena-Crowley relationship as well as Rowena's (Ruth Connell) plans.
The episode begins in Worcester, Massachusetts. A spirit possession makes a man kill himself outside of a church after a priest absolved his sins during confession.
Crowley (Mark Sheppard) confronts his mother, Rowena (Ruth Connell), after one of his demons complained about Rowena's witchcraft. Rowena tells Crowley that she feels betrayed and broken-hearted.
Rowena explains she was devastated with her son's decision to help the Winchesters in "Supernatural" Season 10, episode 14 titled "The Executioner's Song" instead of his own mother. Rowena's plan was to get sanction from the Grand Coven, the supreme command of all witchcraft, so she will no longer be forbidden to practice magic.
Sam (Jared Padalecki) and Dean Winchester (Jensen Ackles) discuss the suicide cases as they head to Massachusetts. Dean thinks the cases involve a curse.
Sister Isabella shares to Sister Mathias about her experience of falling in-love with an artist named Piarro before joining the order. Sister Isabella did not reveal what happened between her and Piarro when Sister Mathias asked her.
Dean tells his younger brother the victims were connected because they were all Catholics. Dean thinks the cases involve a demon possession.
A married couple heads home after their confession. A vengeful spirit possesses one of them. The wife wakes up in the middle of the night, sees her husband in the kitchen, calls him a liar and then kills him using a pair of scissors.
Sam and Dean head to the church to investigate on the married couple. The hunters learn from Sister Mathias that the husband cheats on his wife.
Sam dismisses the practice of witchcraft on the cases. Dean suggests a ghost is responsible for the husband's death.
Crowley calls Rowena to inform her that he has captured Olivette, the high priestess of the Grand Coven. Rowena reveals to Olivette during their conversation that they are inside the palace of her son, the King of Hell.
Sister Isabella reveals to Sister Mathias that her family sent her to a convent after Piarro rejected her love. It is further revealed that Isabella's failed love story happened back in 1520 in Florence, Italy.
Rowena tortures Olivette for banishing her from the Grand Coven. Then, Rowena tells Olivette that she will get what she wants from the Grand Coven's high priestess. Olivette responds that what Rowena wants no longer exists because the Men of Letters tried to destroy the Grand Coven.
Dean confesses to the priest that he is a womanizer and he struggles with life because of the Mark of Cain. After hearing the Winchesters talk about their case, Sister Mathias looks for Sister Isabella.
Meanwhile, Sister Isabella's spirit possesses the priest after he stepped out of the confession box. Sister Mathias discovers in Isabella's journal that she killed Piarro out of jealousy and rage after seeing him in bed with a woman.
Sister Mathias calls Sam and Dean for help. The nun tells the hunters that Isabella's journal and other things found their way to the church.
Dean tells his younger brother they are dealing with a vengeful spirit. Sam believes something ties Isabella's spirit to the church.
Rowena continues to torture Olivette for information on the Men of Letters. The red-haired witch discovers the surviving members of the secret organization are Sam and Dean Winchester.
Dean and Sister Mathias try to locate Isabella's spirit. Sam finds out in Isabella's journal that Piarro used her blood and part of her finger in the pigment of his painting.
Dean finds the dead priest at the altar. Dean tries to bring Sister Mathias to safety but it is too late because Isabella's spirit possessed the nun.
Sam finds Isabella's painting in the room. Sam burns the painting before Isabella could kill Dean.
Rowena turns Olivette into a hamster. Rowena suddenly becomes interested with the Winchesters so she starts asking Crowley about them. Crowley tells his mother that whatever relationship he has with the hunters is his own business.
Sam and Dean discuss in the car about their problem with the Mark of Cain. Sam believes they will find a way to get rid of the mark. Dean shows no interest in finding the cure.
"Supernatural" Season 10 returns with episode 17 titled "Inside Man" on April 1, Wednesday night at 9 p.m. ET on the CW Network.