This novel is difficult to place in the Charmed series timeline because Paige states that Phoebe has already started working at The Bay Mirror, but Phoebe says she is still engaged. This creates a problem because she started working as the advice columnist in the episode after she got married (Marry-Go-Round). Suffice it to say, the novel is set around the time of episodes 15 and 16 of Season 4.
Wnen Paige suggests they attend a Wiccan convention near Las Vegas, Piper and Phoebe don't want to go. Then Darryl reveals that some Wiccan practitioners have gone missing in the area. It initially appears a minor concern until the discovery that every vanished Wiccan was a prominent figure in their Coven, all possessing actual powers; one received premonitions about people by touching an object they had been in contact with, another could cleanse auras, and a third could see through solid objects. So they take up Paige's idea as being a good place to attempt to track down the demons or warlocks responsible, leading to a confrontation with a group of Egyptian demigods called Anubi who drain the blood of Wiccans for their own ends.
However, the true villains are revealed at the conclusion to be, not the Anubi—who simply attacked the gathering and had no connection to the previous abductions—but three sisters—possessing the powers of flight, invisibility, and telekinesis respectively—seeking to claim the Charmed Ones' powers—as well as the powers of the other kidnap victims for themselves, only to be undone before they can complete the ritual due to their ignorance of Piper's powers (They were only aware of her ability of molecular immobilization and not her power of Molecular Combustion).