This is the first and only Charmed book with 3 stories in one and each Halliwell sister has her own story.
Phoebes is Samhain which is set on Halloween and she becomes possessed by one of her ancestors and has to find her demon husband.
Paiges is set at Yule where she gets trapped in a nightclub where a demon wants to create everlasting night.
Pipers is set on Imbolc, she thinks she is pregnant and when Paiges powers go scatty she worries whether having a half whitelighter/half witch child will cause a lot of problems.
I really enjoyed this collection, each story is only around 60 pages long so you can easily read them in one quick sitting. I have nearly all the Charmed books and would be happy for them to carry on even though the show has ended, but sadly it looks like no more are coming out.