The following version of this book was used to create the guide: Cooney, Caroline B. Goddess of Yesterday. Dell Laurel-Leaf, 2002.

The novel starts with the protagonist, six-year-old Anaxandra, being taken away from her home island by King Nicander as a hostage to get her father, Chrysaor, to try to get him to give Nicander gold so he can satisfy Apollo. She is told that she will never go back home, and she gives up the location of her father's treasure by accident, which Nicander's men steal. On Siphnos, Nicander's island, Anaxandra meets Callisto, his daughter. After a year or so on the island, Nicander brings a mining engineer there to try to revive the gold mine he had that collapsed against his wife's wishes; Petra believes it collapsed as punishment and she does not want him to test Apollo.

Time jumps forward to Anaxandra at age 12. Siphnos is attacked and conquered, and Anaxandra watches Nicander, who she now sees as a father figure, get stabbed in the back. She scares off the remaining pirates by pretending to be Medusa. After a few days left alone on the island, Menelaus, the king of Sparta, appears on his boat. He assumes she is Nicander's daughter, making her a princess, and she does not correct him; he vows to take her back so she can live like a princess. On the way back, she overhears him talk about Paris, a son of Priam of Troy who killed another young boy, and then his conviction that Sparta is unassailable. Anaxandra wonders if Paris will try to find a way to invade, as he is to come visit.

At Sparta, Anaxandra marvels at the noisiness and bustle. On the way home, a nobleman named Axon asks to marry Anaxandra even though he wonders why she is not sick like Callisto, Nicander's real daughter, was. He also notices her hair color is different. She staves Axon's advances off and they eventually ride to Menelaus's home. Helen, Menelaus's wife and the daughter of Zeus, is skeptical that Anaxandra is Callisto, but Menelaus tries to soothe her doubts rather unsuccessfully. Later, Helen accuses Anaxandra outright of not being Callisto as she gets used to living there. An old slave, Aethra, warns Anaxandra to stay away from Helen.

Paris arrives in Sparta shortly thereafter, and he and Helen flirt openly. Menelaus openly criticizes Paris and makes fun of him because he will likely never be king of Troy since he is so far down the line of succession. Commanders in Sparta notice that Paris brought warriors on his ships, but Menelaus brushes off their concern. After a few days, Menelaus is summoned to Crete with news his grandfather has died, and the Trojans attack with Helen's help. Helen vows to marry Paris, as the two have fallen in love. Hermione, Menelaus and Helen's daughter, tries to kill Helen when she learns she is to be sent to Troy with her mother and Paris, and Anaxandra goes in her stead in disguise. Anaxandra rides on a boat to Troy; the journey is difficult and rough.

Eventually, they arrive at a port city called Sidon. The ship's captain, Zanthus, apparently took care to see that Anaxandra and Menelaus's son, Pleisthenes, did not die, even though Paris commanded that they should. Helen then finds out that Anaxandra is there instead of her daughter, and she allows her to stay on as a slave to Pleisthenes as long as she shaves her hair. Paris kills the king of Sidon that night and sacks the town.

Everyone arrives in Troy after this. Cassandra, a sister of Paris who is cursed to prophesy the future and have no one believe her, says not to let Helen in the city but is ignored. Anaxandra is to live with Andromache, a princess who is betrothed to the eldest son of King Priam, Hector. Anaxandra realizes that Paris has to obey Andromache because she is ahead of him in the line of succession. Later, they ride horses with Hector and his friend Euneus, who takes Anaxandra riding and kisses her. She goes into town the next day disguised as a boy to buy a slingshot and meets Euneus there, mortified that he is seeing her with her shaved head. He gifts her a puppy and says he is leaving to Lemnos for the winter, where he is king. That night, Troy learns that Helen is pregnant with Paris's son.

Anaxandra goes on to tell Cassandra her true identity, and Cassandra says the gods have cursed her for her lie. She says to stay out of Helen and Paris's way. Several months later, Menelaus's ships arrive at Troy to invade. Anaxandra tells the slave Aethra about her identity while the fighting goes on. Priam believes the war will be short, but Hector thinks there will be more fighting than they think. Anaxandra learns that Paris is trying to kill Pleisthenes and takes the poison away while the Greeks lay waste to the Trojan forces. Anaxandra disguises herself as a boy and takes Pleisthenes out of Helen's room and tries to sneak him back to Menelaus, but is caught. She is banished to live as a slave in the tunnels underneath the temple of the king, but she prays to her goddess down there who leads her to a way out.

Anaxandra learns Paris is plotting to leave Pleisthenes on the street to be killed among the fighting. She kills the slave who is leaving Pleisthenes there and takes him away. She successfully guides him to Menelaus and then tells him her real name and identity, and he accepts her and gifts her the island of Siphnos. He arranges for her to go to Lemnos to stay with Euneus while the battle rages.