Whitney keeps Chad company as he waits on tenterhooks for the computer to finish processing the DNA matches. Grace again urges Eve to tell T.C. the truth about her past. While a shuddering Kay and Miguel look on, Evil Charity calls upon the dark forces to take possession of Coach Russell. Meanwhile, an enraged T.C. becomes overcome with evil intent and begins throttling Julian. Luis struggles to keep Sheridan calm as the oxygen level in the vault falls perilously low. Manipulated by the forces of evil, T.C. continues his vicious attack on the hapless Julian. After Chad finally intervenes and pries T.C. loose, Charity turns her attention to ruining someone else's life and Miguel is alarmed to realize that his big brother is now in her sights. Later, Hecuba reveals herself to be masquerading as Charity and proceeds to put the teens in peril yet again. Luis is astonished to see a tearful Sheridan cradling his dead body in her arms. Chad comes to a startling conclusion about his parentage.
As a weeping Sheridan grieves for her lost love, Luis begins to feel his soul being drawn upwards towards heaven. Eve's fears about her husband intensify after T.C. again vows to kill Julian with his bare hands. Timmy and Tabitha watch through the magic mirror as Hecuba ties Kay and Miguel down beneath a slowly descending pendulum with a razor sharp edge. Julian admits to Alistair that Chad seems somehow familiar. Meanwhile, Chad explains to a skeptical Whitney why he thinks Julian may be the very bigot who fathered him. Drifting skyward, Luis catches a glimpse of his father's file and fights his way back to life. Hecuba returns to the cave to polish off her next two victims. T.C. flies into a rage after overhearing Chad speculate about his paternity. Tabitha gawks in disbelief as Timmy suddenly deserts her and begins sucking up big time to Hecuba. Grace asks Eve if she's certain her son died at birth.
In the hospital, Grace again asks Eve if Chad could be Eve's son. Eve flashes back to the first time she met the boy, and she realizes that there was some kind of spark at the time. She even wonders if the reason why Orville said to keep Chad away from her daughters was because they were brother and sister. After enough doubt is sown, Eve asks Chad if he knows his date of birth. He doesn't, but he tells her that his birthday was usually celebrated on August 14th. Eve returns to Grace and tells her that Chad's birthday is nowhere near the date on which Eve's son was born. Eve is relieved about this, because she can see that Whitney is falling in love with him. Meanwhile, Whitney offers to broach the news that Chad is alive to Chad's birth mother, once the woman's identity is determined. Chad and Whitney kiss, as the computer indicates that the program is complete. We do not see the results of the program.
Sheridan and Luis sneak out of the Crane family archives as Julian and two guards investigate the sprinkler system and the deliberate short that Luis had caused in the electronics. At Alistair's urging, Julian discovers that Katherine Crane's diaries are missing, but the file on Martin Fitzgerald is still there. They realize that Julian must destroy the file. Back at the cottage, Luis and Sheridan discover (a) that Katherine made a note of someone being seen as a threat to the family, and (b) that someone has sliced out numerous pages from the books. Luis describes his out of body experience to Sheridan and remembers that he saw a file about his father, on a high shelf.
As the unholy slicer-dicer comes closer to killing Kay and Miguel, and as Tabitha stands tied up in a pot of hot water, Timmy convinces Hecuba to create a door that would cause a draft and increase the fire under the pot. He then leaves, ostensibly to get martimmy ingredients (from an unknown location) ,but really to untie Miguel's hands. Miguel frees himself then Kay, telling her that it was love for Charity that loosened the ropes. Timmy quietly agrees. He returns to Hecuba's lair with martimmy ingredients (from WHERE???) and confirms to Tabitha that his turncoat routine was just an act. As Hecuba sleeps off the overworking of her power, Timmy frantically tries to undo the ropes. Miguel tells Kay that he knows what weapon will get rid of the evil witch in her lair.
Ethan decides to take his bride on a whirlwind honeymoon through Europe but Theresa is forced to throw cold water on his grandiose plans. As Timmy struggles to untie his princess, Tabitha apologizes for questioning his loyalty earlier. Back at the cottage, Luis finally recalls what he saw during his out of body experience. Hecuba awakens from a nap and instructs her new little groupie to bring Tabitha's pot to a boil. Miguel speculates that he and Kay can use the magic box they saw in the mine shaft to vanquish the evil which threatens Harmony. Crestfallen to realize that he can no longer afford luxuries like an expensive vacation, Ethan renews his pledge to track down the person who exposed the truth about his paternity. Alistair orders Julian to destroy the file on Martin Fitzgerald. Rebecca clashes with a seething Ivy once again as the future Mrs. Crane stakes her claim on the mansion. Hecuba catches Timmy trying to release Tabitha and binds him to the post alongside his doomed friend.
In the hospital, Grace again asks Eve if Chad could be Eve's son. Meanwhile, Chad and Whitney are unable to view the results of the completed DNA program, because Eve's password must be entered. They call for her, but she puts off typing it in so much, that she still has not done so by the time she is called on another emergency. She is clearly afraid that he may turn out to be her son, after all, and she wants to talk to him about the possibility beforehand. The information remains unrevealed at the end of the show.
Theresa and Ethan run into Ivy at the hospital. They are re-doing all of the wedding paperwork (including blood tests, which explains why they're at the hospital), using the name Ethan Winthrop instead of Ethan Crane. Ivy is pleased to hear that he has chosen her maiden name, but considers it necessity, not honor to his mother. He again blames Sam for the prom boat disaster. When Sam walks into the hallway with flowers that he will take to Grace, Ethan tells Sam that he will see to it that Sam pays for his mishandling of the prom boat situation. Sam reminds Ethan that the boy is no longer on the Police Commission. A frustrated Ethan realizes that his power and credentials are slipping away.
Later, Ethan and Theresa ask Chad and Whitney to be the best man and maid of honor at the Winthrop/Lopez-Fitzgerald nuptials.
Miguel and Kay have found the box that can destroy evil. Miguel opens it, and the light puts Hecuba through agony as she weakens. Timmy & Tabitha, still tied up in the cauldron, are also hit by the light, but it merely serves to loosen the ropes that bind them. Concluding that an image of Charity in the light is really her, and that closing the box will free her, Miguel closes the box against Kay's objections. Once it is closed, he realizes what Kay knew all along: the image was a deception to get him to close the box.
Tabitha, who has hurt her ankle, agrees to help a severely weakened Hecuba. Hecuba must shrink to a tiny size, so Tabitha can put her in a bottle and carry her out of the lair. The requirement for Charity's freedom is that the evil witch must be destroyed in her lair, and the bottle will help protect Hecuba. Once Hecuba is in the bottle, Tabitha instructs Timmy to keep his hand over it until she (Tabitha) can find the stopper and trap her (Hecuba) inside. Hecuba catches on quickly and shoots lightning bolts onto Timmy's hand.
Fr. Lonigan visits Grace in the hospital and realizes that her anger runs very deep. As he offers comfort and reminds her that her wedding vows included "for better or worse" they begin to take a walk outside the hospital. They see and hear Ivy asking Sam if he ever shared the same passion with Grace that he did with Ivy. Sam and Ivy have not yet seen Grace and Fr. Lonigan. As Sam prepares to answer, Fr. Lonigan advises Grace not to torture herself, but she wants to hear the answer.