In the desert, at the Nexus of the All, Darryl is commanding the small army gathered together to defeat the swarm of demons escaping from the dome. Leo, Prue, Coop, Henry, Knox, Miss Donovan, Elise and Tyler use the magical weapons forged by Gynnis to fight off the demons.
Meanwhile, Piper, Phoebe, and Paige make attempts to orb into the dome and Paige finally succeeds by learning to harness the energy it releases. They enter and find it bigger on the inside than it is on the outside, and find their powers reaching their maximum potential. Paige is able to scatter a demon's orbs all around the world, Phoebe's powers are useless because the demons turn out to just be mindless automatons (but she is able to use her martial arts to kick ass), and Piper is able to blow up nearly the entire army.
Afterwards, the inside of the dome starts changing thanks to the sisters' effect on it and they spot the Empyreal Sword and the Grimoire in the center of a pentagon, though it's being protected by Rennek who still has control over the world's magic.
Back on the battlefield, Glynnis kills a demon with a Charmed cannon and it falls and breaks a hole into the dome allowing Prue and Leo to break their way inside.
Rennek has the sisters tied up and tells them they will never win the fight because he can create an endless supply of soldiers. Phoebe tells him that his plan will fail because his soulless automatons have nothing to fight for, but Rennek tells her they fight for him because he has complete control over magic. Piper scolds him about not learning that magic isn't about having the most power. He magically muzzles Piper but she continues to think telepathically, "It's not about power. It's about finesse." And from inside of the dome she is able to use her mind to manipulate the molecules of the demons attacking their friends and family outside, turning them back to their original forms that Rennek transformed them from: flowers, sand, etc.
She, Phoebe, and Paige then proceed to telepathically communicate with each other and cast The Power of Three Spell, non-verbally, breaking themselves free. They then create another spell that channels the power of matter, time, space, the elements that bind the worlds and the magic of the entire Halliwell line to undo what Rennek has done but it fails as Rennek still has control. Leo then charges at Rennek but he's repelled.
Rennek and Leo have an argument of ethics and morality with Leo telling Rennek that the powerful and the powerless have decided to fight back without supernatural guidance in response to Rennek pleading with him to allow people of this world to choose their own destiny. Rennek tells him that not even the three Halliwell sisters can stop him. Prue then charges at him, reminding him that there are four sisters, and grabs the Empyreal Sword out of the Grimoire, absorbing it into herself, and casts a spell that gives her ownership over both the items and vanquishes Rennek. Prue (now covered in various Greek letter symbols) then casts a follow up spell to reconnect the realms at that hallowed space and to erase all humanity's memories of the last six months, however, making sure that they never truly forget it just in case magic is ever revealed to the world again. "For most people, the past few months will be kind of a dream. Just outside the grasp of their memories."
Prue has turned the Nexus of the All into a complete replica of the Manor and everyone's inside. "Patience"'s body has now become Prue's to have (she is still covered in symbolic tattoos). Phoebe is reveling in the fact that she can fly now instead of just levitating but only for a few short moments. Prue tells her that the dome allowed her to tap into the point her power will grow to and it's going to take time for her to reach it naturally. Darryl and Prue say their goodbyes to each other as Darryl is more than ready to get back to his family but Paige accidentally orbs him back home prematurely. Leo's wings are gone for good and Prue talks to him about how the Grimoire is now inside of her as well but he lets her know that a lot of good came from it and she has a brand new control over magic.
Piper then has Paige orb the guys to Victor to relieve him of babysitting duty. There's a knock on the door which is revealed to be Cole who is now a messenger from the Heavens. The Elders haven't forgiven him for his past crimes or allowed him to move on but they did appreciate his sacrifice in allowing Prue to return to Earth instead of using the power to escape Limbo himself. Cole tells Prue that the Elders were impressed by what she did and he's here to inform her of her new role in the universe. Because she absorbed the Sword and the Grimoire, she is now the conduit that holds the realms together. She is the caretaker to the connection and can never leave the Nexus. Cole is now her personal messenger: He can move freely through the realms and visit San Francisco whenever he wants and after a few centuries of service, he might earn the right to move on. Phoebe asks him if he's back in their lives and he responds that only if he's welcome and he'll stay away unless Prue needs him to go see the family since she's bound to the Nexus of the All. Prue appreciates Cole's company in this Manor since it was going to be just her. Piper says that Prue can make it look however she wants, but she's happy with the way it is. She says that it is just like home, especially with Phoebe forgetting to close the door that she telekinetically closes, as per tradition.