Pros: The plot, the magic
Cons: Cole being vanquished
I bought Season 4 of Charmed because I loved the first three seasons.
Season 4 starts off very sadly as Piper (Holly Marie Combs) and Phoebe (Alyssa Milano) deal with the loss of their eldest sister, Prue (Shannon Doherty) who was murdered in the last season by a demon. I actually cried watching Prue's funeral and felt that the presence of a half sister named Paige (Rose McGowen) wasn't enough to make up for killing of Prue.
Paige (who looks extremely thin and pale, almost like a vampire) comes to the sisters to help bring back the Power of Three which was lost when Prue died. The sisters regain their powers and start demon hunting again, bringing Paige along for the ride to learn as she goes. Cole (Julian McMahon) is also back in this season and its interesting to watch as he battles his evil side because of the good Phoebe brings out in him. Which was sweet although he eventually ends up as the Source of All Evil and must be stopped by the Charmed Ones. Too bad, I really thought he and Phoebe were going to make their relationship work and I liked how they had an ally who could tell them what was going down in the demon world. I hated to see him go.
Leo (Brian Krause) has a surprise of his own when he tells the Charmed Ones near the end of the season of how he has become an Elder and how they now have a new whitelighter named Chris (Drew Fuller). I loved the way drama was caused by Cole reverting back the dark side and it was interesting to see if Phoebe had what it took to vanquish the man of her dreams.
Another thing this season provided was being able to see Phoebe follow Cole to become his evil Queen of the Underworld. Paige isn't as good as Prue in this season, but she does grow on you after a while. I guess it took time to get used to not seeing Prue around anymore. One thing I did hate though was the way Paige's facial expressions were. I mean, it seemed as if she has a nervous tic or something and her smirk was unbearable, but other than that, this season is an excellent addition to your Charmed collection and the plot twists will rock your mind.