As the “Starry Messenger” comet approaches Earth, heralding the culmination of the Witches’ dark plan, the Countess Marburg makes a long-awaited acquaintance with one who plays a pivotal role in her and the others’ cause. Mary and Wainwright grow closer, their mutual affection heightened by recently discovered revelations, but as the pair plans for the next steps along the journey she has in store for him, another - displeased with these recent developments - takes matters into his own hands. Even as Mary prepares to strike against the Countess, she receives news that shakes her to the core. As Cotton tries to reason out information recently revealed to him, the betrayal of a recently made ally may spell his mortal doom. Meanwhile, Anne continues to glean knowledge from her dead father’s writings, and a long-brewing feud reaches a tipping point, culminating in a surprising and potentially game-changing disclosure.
Mary is in her chambers watching the clock of doom as it maps the position of the comet when Samuel Wainwright begins to kiss her passionately and she tells him he must destroy all evidence of her witchcraft if he wishes to continue his enlightenment stating there can be nothing that leads back to her. Samuel does not look pleased as this would mean having to destroy all of his work but is later seen burning everything he has learned since arriving in Salem including the malum.
In the morning Mary is preparing her son's breakfast when Tituba arrives and asks if she should take it to him but Mary tells her no that she has another task more suited to her skills- revealing the maggoty head of Increase Mather. Tituba is shocked and chastises her for attempting necromancy without her as it is dangerous but Mary disregards her uses clearly upsetting Tituba and tasks her with disposing of the evidence. Mary soon goes to her son's room and finds his bed empty and is clearly worried but is greeted by the Countess Marburg who enquires if she has lost something. Mary demands to know what she has done with her son and is soon devested to learn the truth about her son, he must be sacrificed to complete the grand rite and become the vessel for the devil something that was kept from her from the Essex witches. The countess is surprised that she didn't know this and tries to console her stating it was something she had planned for her own son many years ago but it wasn't meant to be. A heartbroken Mary tells her that she won't do it causing the Countess to threaten that unless she meets her in the crag to baptize her son in hell blood to complete the grand rite she will kill him, Mary lunges at the countess but she disappears leaving Mary alone in the room weeping.
Elsewhere Hathorne visits Cotton who at first refuses to answer the door shouting at them to go away but he enters anyway accompanied by two of Salem's guardsman and shows his distaste for Cotton as he is clearly inebriated. Hathorne informs him that he has been in touch with the Boston elders who informed him of his banishment, that the elders forbade him from returning to Salem but Cotton tells him he was sent there by a higher power to defeat the witches. When Hathorne attempts to have the guards arrest him, Cotton tells him that he has proof that it was the witches that sent the pox and explains what he has seen in the crags but Hathorne is doubtful. Cotton tells him that the good doctor Wainwright has seen the same thing and if he doesn't trust himself he can trust him but when they visit him, Wainwright pretends that he never saw such a thing. All three men travel to the crags but when no one can see the devilish black pitch that Cotton spoke of only the bodies of the victim's of the pox Hathorne orders the guards to take him away as Wainwright looks on.
At the Sibley House, Mary who is still clearly devastated over recent revelations shatters the glass of her night dresser telekinetically but is disturbed by the arrival of Sebastian Marburg who applaud's her. Mary believes he has come to rub more salt into her wounds while he tells her that his mother doesn't even know he is there and uses his power to mend the broken glass. The Baron tells her that he saw her with Wainwright last night and Mary admits the only thing that means anything to her is her son and offers herself to him if he gives him back to her but the pair are interrupted by the arrival of the doctor. The Baron continues to tell the doctor that Mary has entrusted him with his initiation as it would not be possible for Mary of her standing to be seen spending so much time with another man as she is already married while secretly speaking with Mary telepathically advising her to go along with it if she wants to be reunited with her son. Mary tells the doctor that Sebastian is one of the witches and a trusted friend. She sadly watches as he leads the doctor out of Salem to his doom.
At the Hale cottage, Anne is in the secret chambers as she reads a passage in her father's book of shadows. He writes that he sealed the book so that only if she had attained some skills and a familiar would she be able to read what it contains and if she is reading it now he knows that he is dead, that she has traveled down the dark path but he is always with her. Anne clearly upset turns to look in the mirror as she wipes away her tears and see's a hideous demon beside her horrified she turns to find the creature but it is gone. Elsewhere Sebastian continues to take Wainwright to the crags while the good doctor is unaware of his duplicity as the pair converse Sebastian pushes the doctor into the black pitch and watches as he is consumed by the hell blood promising him he will comfort Mary in his absence.
Later that night, Mary summons Tituba to her bedroom and informs her that the Countess has stolen her son and is preparing him for his sacrifice something that she had kept from her. Clearly fearing the repercussions of her action's she tries to leave but Mary telekinetically closes the door and questions her in why she deceived her for all these years. Mary is shocked when she reveals that she did it because she knew she would never have gone through with any of it if she knew the truth. As the pair confront each other Tituba reminds her that they sold the boy to the devil himself like she had been sold as a slave time again, that all the world would be hers if only she would harden her heart but Mary tells her she never wanted the world only a real heart and all the love that went with it. Tituba questions if she found any love when she was having sex with Samuel Wainwright as the Countess stole her son causing Mary to strike Tituba, who in turn throws hot coals at her mistress before trying to flee but Mary appears in front of her and holds her against the wall before she telekinetically summons a knife and presses it against her chest fully prepared to kill her. While Tituba tells her to do it she also states that only if she spares her life would any of the love that she has lost be returned to her, a confused Mary asks how and is shocked when Tituba reveals that John Alden is alive.
Tituba takes Mary to the hidden chambers in the Sibley house who is horrified to find John Alden tied up. She tries to reassure him that she hadn't known he had been kept like this and had believed he had died but John tells her he doesn't know how he had ever loved her and asked her why she had done the thing's she had. Mary clearly upset with his confession tells him that she did it because of the Puritan's, who had branded their friends and forbade their love. That she had been trying to create a world without Puritan's, a dream they both had in their youth but John does not believe her as he thinks that she is lying and confronts her. Mary admits of the existence of their son, that the witches had lied to her a thousand fold and plan to kill him. John is clearly emotional as Mary begins to cut his ropes, despite Tituba's warnings who tells her that he is no longer the man she loved but the witch killer but Mary frees him anyhow and forces John to hold the knife to her throat and tries to convince him that they do have a son and that the witches will kill him.
In the Commons, Cotton is placed in a carriage with the guardsman and asks Hathorne if he can see Anne but he tells him that he will inform her of his current state and will be the shoulder she cries on before he takes the driver to one side and reminds him that Cotton must die before they reach Amherst and to say they were attacked by Indians. Back at the Sibley House Mary takes John to their son's bedroom and tells him that the boy asked about his father and that she told him that he was the very best of men before he claimed his name for his own. She explains that when he went off to war she was with child but didn't tell him because she knew that he would have stayed and George Sibley would have ordered his death. Then one night Tituba offered her a solution sacrifice their unborn son but reveals that Tituba and the elders kept it secret that their child was alive being raised in the woods. Then on the night she was fleeing Salem to be with him they brought the boy to her and she couldn't abandon their child again so stayed and begs John to help her save their son. The pair put in motion their plan of attack for the following evening, as the countess takes their son to the crags John will be there to protect him while Mary herself will be on her ship finding her Achilles heel.
While Anne still at the Hale Cottage, continues to learn in how to control her powers from her father's book of shadow's while hearing his voice. She manages to manipulate the movement of objects without the heed of emotion as well as bring a flower to full blossom before she makes it wither in her hands but her father warns her this magic is both a blessing and a curse ominously telling her that He is the curse. As she sees a hideous drawing of the creature she had seen earlier in the mirror she is transported deep to Salem's woods and a terrified Anne flees from the creature screaming for Cotton to help her but it captures her and begins to rip away her clothes but afar away Cotton hears her screams and as the comet looms over Salem the Countess aboard her ship tells the young boy that he will one day be that star but Mary standing in her balcony watches as John leaves and promises her son that she and his father are coming for him. While Tituba pays for her duplicity having been left tied up in her blood chamber.