turn them against each other

Evylina came up with her plan. It would require a lot of powerful magic, but she had plenty in store. They day came to spring the trap. She used telepathy to appear in the form of a spirit. Her first target was Piper, who had gone into work early and was alone in her restaurant.

"Piper Halliwell," said Evylina.

"What? Who's there?!" said a startled Piper.

"I am a friend," said Evylina, "I don't have much time. You and your sisters are in grave danger!"

"What is it, and how can I trust you?"

The spectral vision of Evylina looked into Piper's eyes, and Piper grew trustful of her.

"Trust me. I am a friendly witch, just like you," said Evylina. "Your sister Phoebe is not who she seems."

"What do you mean?"

"She has been captured and replaced with doppleganger. Phoebe is being tormented by evil warlocks, just like I am, but I managed to briefly escape, though not in person. The doppleganger means to kill you and Prue."

"What can I do?"

"The only way to kill the doppleganger is to cut off her head. That is the only way. Once you kill the doppleganger, your sister will be freed from her torment. The Doppleganger will lie and try to decieve you. Do not listen to her. She will even try to get you to harm Prue!"

"Oh my god!" said Piper.

"I must go!" said Evylina. "They are coming!" She vanished.

A moment later, an apparition appread to Prue at work. She gave the same story, but this time, Piper was the doppleganger, and the only way to kill her was to burn her alive.

Prue listened earnestly and with fear and determination.

Finally, it was Phoebe's turn. Evylina convinced Phoebe that it was Prue who was the evil doppleganger, and the only way to kill her was to rip her heart out.

Phoebe was still at home and listened with disbelief, but she was determined to save her sisters from the evil Piper doppleganger.

The sisters were to all meet at home that evening for pizza and rom-com movie night. It was still early in the day, and they each had to devise a plan to kill the evil doppleganger. Prue called Phoebe to warn her about Piper, but Phoebe did not believe the woman she believed to be an evil doppleganger, but she played along. Phoebe called Piper, and Piper called Prue, but each one was calling the sister who believed her to be an evil doppleganger.

Evylina watched all of this on her magic mirror.