In the depths of the Underworld, a high level demon, Ayacha, is talking with a low level demon about his plans to attack the most powerful family of witches the world has ever known. He wants them dead so he could win power and become the leader of the Underworld.
Meanwhile, a car parks in front of the Halliwell Manor and the girl inside looks at the manor. Inside, the entire family is all reunited to celebrate Piper Halliwell birthday. All together but one, Prue Halliwell. Phoebe is preparing dinner under her daughter Cassandra and her niece Pandora supervision. In the main hall, Wyatt is wondering why his cousin Prue hasn´t arrived yet but at that moment the girl arrives. The same girl that parked in front of the manor moments before is Phoebe´s eldest daughter, Prue. She says that something got her stuck at P3, the club her Aunt Piper owned and she owns. She goes say hi to Piper and asks for her mother only to hear she´s in the kitchen cooking.
Piper leaves the room heading to the kitchen to check on Phoebe who is having troubles cooking dinner. The food is burned and the solution that comes to Phoebe´s mind is to use magic to make it look good. Piper warns that is not a good idea to use magic for personal gain but Phoebe does it anyway.
Dinner is finaly on the table and it´s time for the toast when, suddenly, out of nowhere, a demon comes into the house and throws an energy ball straight to Phoebe making her fly through the window and ending up in the back garden. The demon tries to use his powers on them again, but Melinda and Prue work together to vanquish the demon. Then, they all run out to the garden only to find out Phoebe is death.
The police arrive at the house, but Chris and Henry doesn´t know how to explain what happened to the inspectors. Meanwhile, Paige is trying to comfort Piper on Piper´s bedroom telling her that they can go after the demon sent to attack them. Piper is not convinced. She says that they are not young anymore so Paige says that their kids could do it but Piper is not convinced. Pandora comes in and tell them the inspector would like to talk to them.
In the attic, Prue and her sisters, Charlotte and Cassandra talk about a way to reverse the situation. Prue is desperate and is willing to do everything she can to bring her mother back to life. She gets an idea, but Coop comes in and hears that she´s wants to use her cupid´s powers to go back in time. Coop tries to make her give up on that idea unsuccessfully. Wyatt and Chris reach the attic only to hear Prue´s plan: going back in time to save Phoebe. At first, Wyatt doesn´t like the idea but ends up agreeing with Prue with a condition: he goes with her. Chris decides that he wants to go too. Prue is not happy with their decision but ends up agreeing.
Going back on time is tricky. They went into the future. 10 years in the future. There, Prue sees herself as a mom. Apparently she wasn´t thinking well on Phoebe and ends up in a time where she was a mother. Wyatt looks surprised, but Chris not that much. Future Prue tells the past visitors that they need to focus on Phoebe. Once again, time travel is tricky. This time the end up almost 15 years before the time they wanted to go to. There they meet the Charmed Ones and they see themselves as kids. Past Wyatt and past Prue fighting, which is something that they do a lot, and past Chris trying to make them stop fighting. A little chat with their younger versions leaves them with a strange feeling. Little Prue tells adult Wyatt that she dreamed of him being her prince. Adult Prue doesn´t know how to explain that while adult Chris laughs.
Wyatt, Prue and Chris tell their mothers and Paige the reason they went back in time. The three Charmed Ones decide to go with them into the future and help them to prevent the sad happening of Phoebe being killed by a demon. So they do. They arrive just in time to stop the demon from doing it. They are surprises by the arrival of the time travelers that explain what have happened so far. Coop takes back to their time the Charmed Ones from the past while the others try to figure out what to do.
The demon that was frozen is taken to the attic where he´s inside a crystal cage. It´s a Sender demon, a kind of demon that uses to do favors to high level demons. Prue tries to get something from the Sender demon but get´s nothing. Phoebe has a premonition and they get to know that a demon named Ayacha sent the Sender demon. Somehow the demon finds a way to leave the cage and Prue watches it and her reaction is to use her powers to stop the demon but, not knowing how, she does it by using an explosive power which is something she doesn´t possess. The demon blows up. Later they´ll find out that Prue has gained a new power, Advanced Telekinesis. Prue freaks out about it because she doesn´t know how to control it.
After getting Prue to stay calm, they start drawing a plan to stop the demon. Ayacha sends another Sender demon but this time he thinks it´s better to start with something easier. Cassandra, the youngest of the family, goes out to the garden to clear her mind where is surprised by the Sender demon and his attack. Prue and Melinda go to help Cassandra who is trying to get away from the demon´s attack. The Sender demon is vanquished by Prue who uses her new power, unintentionally.
After that, the girls go inside where Wyatt is surprised to hear that Prue vanquished a demon using her new power. Wyatt says that he and Chris will go to the Underworld alone but Prue doesn´t agree with that as do the others whom think it could be a good idea the nine kids go to the Underworld and fight together against the demon. That´s when Prue remembers she has a spell she created when she was a kid and that the spell may be good to use on that demon. Prue and Phoebe explain to the family that the spell was used by the nine already when they were little kids but only Phoebe knew about it. The kids decide to go to the Underworld and finish Ayacha once and for all.
In the Underworld they split into groups of three being Wyatt, Prue and Chris leaders of each group. Prue´s group is the first to find Ayacha. Prue asks Junior to find the other while she tries to face Ayacha. After some attack from Ayacha and some good work deflecting the attack from the kids, the nine use the Power of Nine spell vanquishing Ayacha for good. Before turning into dust, Ayacha reveals that the nine kids are known by the magical community as the Destined Ones.
Back at the manor, the next day, they´re ready to celebrate Piper´s birthday. Prue is outside the house and Wyatt joins her. They talk about what happened and Prue tells him she´s not going to lose her mind thinking about the future. Wyatt is curious and asks her about the prince dream thing only to her that he´s not her prince. Chris comes out to tell them lunch is ready. Before going in, they say that it´s their time to take over. As they head back into the manor, Prue, telekinetically, swings the door closed behind them.