A demon is poaching humans' Guardian Angels as protection against the new power on the horizon.
Paige is smitten with Agent Brody, so she willingly helps him track down the demon. That may not be a good idea.
Piper is focused on exorcizing Leo's demons with a handy vision quest.
Phoebe is still suspicious of the men in her sisters' lives, but she agrees to help them out.
Agent Brody drags Phoebe and Paige to a burning building, where he predicts someone will jump but miraculously survive. Phoebe is skeptical, but he turns out to be right. This is not cause for celebration - he also predicts that innocent will suddenly die senselessly. He's right - the poor guy gets creamed by a truck. Brody and the sisters can't figure out what happened. Turns out the demon can operate at the speed of light, so he managed to snatch the Guardian so fast no one saw him. Or did he? Brody had helicopters filming the scene, and high-tech imaging reveals dark and light forces surrounding the victim. Brody decides to test the theory by leaping out of the next burning building and having Paige at the ready to see the Guardian-poacher. She does, but the demon takes her Guardian instead of Brody's.
Phoebe mixes up the vision quest potion, and Piper convinces Leo this is the best way to figure out what's up with the scary floaty heads. He's skeptical - especially when he finds out Paige has been stripped of her Guardian, which makes her clumsy and vulnerable - but Piper lays down the law. He goes into the quest, and discovers FutureChris is his spirit guide. FutureChris shows him that family and love is the foundation of everything Leo stands for, convincing him that everything is going to be all right. Not so fast - as Leo is coming out of the vision quest, a scary floaty head zaps him back into it, showing him the dark side of the future Chris promised. The war between good and evil that Leo is fighting, the head claims, will end in the destruction of everything, the eternal void - and the untimely death of his family. If Leo joins them, they can make it stop, and create utopia where good and evil no longer exist. Leo is skeptical.
The demon figures out that Charmed Ones Guardians are much stronger than run-of-the-mill angels, and he wants more. He tries to attack Piper and Phoebe, who are watching over a vision-questing Leo, but the protective crystals that they employed for the quest keep them safe. Paige, who is making a banishing potion with Brody in the kitchen, orbs up to help, but trips when she's trying to be stealthy. She orbs into the crystal circle before the demon can grab her. Brody isn't so lucky - he barrels upstairs to save the day, but gets nabbed for his trouble. The demon takes him as a hostage to lure the Charmed Ones out of the protective circle.
Paige, without her Guardian, is even less likely to listen to reason and goes off to save Brody. Piper and Phoebe try to get to the Book of Shadows in the kitchen, but the demon ambushes them. Phoebe manages to grab his Guardian-snatching amulet, apparently releasing the captured Guardians. Piper finally vanquishes him, but not before he deals them both fatal injuries. The scary floaty head guy tells Leo he can save them, but only if he joins them as an Avatar. Leo gives in.
Paige and Brody arrive to see Leo resurrect the sisters. Paige is suspicious. Piper seems to be suppressing her own doubts. Leo is calm, even serene. Paige asks him if he knows anything about the Avatars, and Leo dodges the question.