Tabitha has been return from the plane of Yig to assist Mary with capturing the ancient power for Yig. Tabitha is still angry for Mary “killing” her years before, but decides to put a truce in place while she seeks the power for Yig. As Kiki, Russ, Jay, and Zach drove past the ancient site, their passing is noticed by Mary who conjures up a hell hound to attack the group. Through some fancy driving by Kiki, they manage to lose the beast.
Upon returning to their office, the gang goes into full research mode to stop Mary and Tabitha from releasing the ancient energy. While Bob continues to pour over the Tome of Nocturnal Crafts and the Book of Exorcism of Witches, a call is place to Father Cavanaugh in Cleveland who helped the gang in Season One re-seal the ancient energy. Father Cavanaugh gives them the name of a local priest, one Father Thompson, who is versed in the occult world and can assist them with holy water and prayer.
George and Zach take off for Ellicott City to retrieve Father Thompson only to encounter a thick fog that has descended upon downtown Columbia. While navigating the drive through the fog, Zach hits a pedestrian. Upon getting out of the van to assist the person, Zach discovers that it is a Zombie! After a brief struggle, George kills the Zombie with a well-placed shot to the head. George and Zach continue their ride to Ellicott City, picking up Father Thompson, and returning him to the office. It is determined that the fog is part of the witches’ ritual for unleashing the ancient energy.
Bob’s long hours of research finally gives a huge clue on dealing with Mary and Tabitha. The gang learns of a ritual that can trap and dispatch a witch from this world. The ritual consists of preparing a liquid (consisting of holy water and magical herbs), painting it into the shape of a circle, placing/situating a witch within the circle, and then performing a chant to dispel the witch.
Zach goes to the mall to pick-up the herbs at the local health food store where he encounters Mary. Mary places a charm on Zach, luring him to the Starbucks for a drink and conversation. Zach has enough of his senses left to text page the gang for help. The gang arrives in full force, dressed in combat gear, masks, etc, and extract Zach from Mary’s clutches. The gang returns to the office and makes the liquid for the ritual, grabs their gear, and heads for the ancient energy site for the final showdown with the witches.
At the site, the gang paints two circles on the ground and watches from the shadows as four figures in robes descend upon the site and begin the final ritual. They are soon joined by Mary and Tabitha. At this point, the gang decides to kill the cultists, which they successfully do. Unfortunately, their deaths begin the final phase of the ritual to release the power. As Mary and Tabitha move forward, Tabitha crosses into one of the circles, at which point Bob begins the three minute long chat to dispel her. During this time, the gang attempts to attack Mary without any luck. During the ritual, Mary ignores Tabitha’s pleas for help and moves towards the energy seeping up from the ground.
Bob completes the ritual and Tabitha disappears in a flash of light. Mary steps forward to harness the energy, only to be thrown back from the area. While lying on the ground, a portal to the domain of Yig opens once more. Yig chastises Mary, telling her that the power would not be hers and that she had lied to Yig about her true intentions. Yig reaches out, grabs Mary by the throat, and pulls her into the portal. There is a flash of light, and the portal is gone.
Columbia is safe once again (for now).