Mortal Enemies/Plot

Plot
In the manor, Paige and Phoebe are taking care of their mortal innocents, while the magic-wielding ones are with Leo at Magic School. In the Underworld, the Source is using Hogan's discord power to turn all mortals against the Charmed Ones, and as Paige and Phoebe go upstairs to the attic, we see it playing out in the eyes of the innocents.

Meanwhile, Piper is scouting locations for her new restaurant. After a couple pages of bad locations, she finally comes across the right one, and that's when her real estate agent attacks her, falling under the discord spell. Back in the manor, the mortals are restless downstairs, so Phoebe and Coop go to investigate, leaving Paige with Henry. Henry tries choking Paige to death, but she's able to telekinetically orb a lamp into his head, knocking him out. Phoebe and Coop run back up to the attic, escaping the horde. Piper is in a knock-down, drag-out fight with her real estate agent, who seems to be getting more powerful as the fight goes on.

Back in the Underworld, The Source is ready to make his next move, leaving Hogan and Neena behind to work on "more important things". Phoebe, Coop, Paige and Henry have retreated to magic school, where Henry is free from the spell (because of Magic School's protection), and feeling guilty for what he's done, but Paige doesn't want to talk about it and tells him that it wasn't his fault.

Piper is frantically driving home, with the whole city out to get her. She gets to the manor and sees all the possessed mortals, but before she can even get worried about that, The Source shows up -- right as Paige and Phoebe orb in. The Source re-introduces himself to the Charmed Ones and tosses some fire balls, which Paige eventually blocks with her orb shield and Phoebe dodges by levitating. As The Source tosses an enormous fireball at the girls, Piper uses a new power which melts the street, holding The Source in place long enough for Paige to orb them back to Magic School (narrowly avoiding the huge fireball).

Back at Magic School, the ladies fill the guys in on who's back, while Leo explains that the Source keeps coming back because every time they vanquish him, they only destroy his demon form, but not his essence. Then, they all stand resolute in their determination to put an end to The Source of All Evil... for good.

Plot analysis by adamreisinger taken from his review of charmed #4