The original gods, the Titans of who Helios is the senior, are in conflict with the Olympians headed by Zeus. 

Circe, a nymph, one of Helios' daughters tells her story. She grows up a strange child, not having the radiant beauty of a goddess but with powers that she doesn't fully understand. She witnesses the punishment of her uncle Prometheus who is being punished by agreement between Helios and Zeus to keep the fragile peace between Titans and Olympians. Prometheus has been brought to her father's halls to start his torment in front of the gods assembled there. Circe secretly offers him support, putting her in conflict with all the gods.

Believing she will never be allowed to marry a god, Circe meets a mortal Glaucos, a sailor, with whom she falls in love and she discovers she has the power to cast spells and manages to make him immortal. However a nymph, Scyilla, steals Glaucos away from her and in revenge Circe turns her into a monster.

When her father discovers Circe's powers and that she has used them against her fellow gods he banishes her for eternity to a deserted island, Aiaia. Her she settles in and develops her skills as a witch.

Various humans cross her path, and if they threaten her (they always do, finding a young woman living alone an unprotected) she turns them into pigs. 

As the centuries pass (she is a goddess and therefore immortal) her only contact is with Hermes who occasionally brings news and messages from outside.

Other visitors appear - Daedelus, who has gained permission to bring Circe to Knossos to assist in the birth of her sister's child using her witchly skills - the child turns out to be the Minotaur and the birth horrific.

Jason and Medea, Circe's niece, arrive at Aiaia fleeing from having stolen the fleece from Circe's brother Aeetes and killing his son (Medea's brother) on the way. 

Eventually, of course, Odysseus, arrives a stays awhile. Circe takes him as a lover and just before he leaves allows herself to fall pregnant by him and, unbeknownst to Odysseus, gives birth to a son, Telegonus.

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