Everyone is dealing with the aftermath of last season's finale - Gideon's betrayal, Chris' death (and birth), and Leo's destruction of an Elder. Plus there's a new force floating around, and no one knows who it is - or what it wants. Piper is more paranoid than usual about the kids. She hasn't left the house since Chris was born, and she's in hyper-protective mode. Leo's lost it - he's obsessed with finding Barbas and wreaking a little well-deserved revenge. Unfortunately, Barbas' fear-mongering powers mean Leo suspects everyone - even the Elders.
Phoebe finds herself a bit distracted, to the extent that she's started plagiarizing from herself and offering the exact same advise to multiple readers. She tells her editor she needs to take a break. Fine, says the editor - we'll hire a ghostwriter.
Paige is on nanny duty, and she's getting restless. Leo is being haunted by an ominous floating invisible head, who warns him to save his son from Barbas That same floating head appears to Barbas, counseling him to take out the Charmed Ones by pushing Leo over the edge and thus leaving the sisters unprotected. Despite being scary and floating and invisible to everyone else, both men decide to listen to the head. An Elder appears to warn Paige and Phoebe that Leo is attacking Elders and is in danger of being "recycled," or sent off to be born in a new body. Paige tries to tackle two problems at once: She sends Leo and Piper to a friend's Hindu wedding while she tries to track down Barbas. Phoebe is left tending to baby Chris outside, and is harangued by the suspicious inspector, who wants to know what happened to Chris. She hands Phoebe a summons to talk at the police station. At the wedding, the officiant calls upon the Hindu's Ultimate Lovers, Shakti, the Goddess of Creation and Shiva, the God of Destruction, to bless the marriage. They chose to possess Leo and Piper while they're at it. Suddenly, Piper is sprouting a couple of extra sets of arms. Shiva-Leo and Shakti-Piper are seriously into each other, which is a problem. If Shakti and Shiva get together, it spells the end and rebirth of the world. Paige and Phoebe send Shiva-Leo off to find Barbas while they try to figure out how to eject the gods from his and Piper's bodies. The sparks between the happy couple rub off on those around them - Phoebe gets amorous when she meets her hunky ghostwriter, Les. There's smooching, and she flees. Paige goes to the magic school for info, only to find it's being shut down now that Gideon isn't around to run things. Hmmm. Piper is attacked by demons while everyone is away. She and her many arms manage to fend them off, but Barbas almost gets to Chris. The sisters try to keep this from Leo, but he finds out and gets destructive. The inspector and Darryl choose this moment to break in, and the inspector gets pummeled by Shiva-Leo's godly powers. Driven by rage, he takes out an Elder, who he thinks is working with Barbas. He's appalled at what he's done. Paige finally manages to eject the gods from their bodies. Piper tells him that no one needs to know what he's done. Paige and Phoebe track Barbas to his lair and vanquish him. Barbas is peeved that the scary invisible floating head sold him out, but vows to be back. Paige has found her cause - she's going to take over the magic school. Piper's time as the ultimate mother made her realize being overprotective just leads to neurotic kids. Phoebe apologizes to Les for objecting to his being her ghostwriter. Leo looks for answers in Barbas' ashes, but is confronted by the scary floating head - who lets Leo know they're gunning for him.