Following the events described in The King Must Die, Theseus leads a Hellenic expedition to conquer Minoan Crete, fallen into anarchy after the great earthquake.

Pirithoos subsequently talks Theseus out of returning to Knossos to meet his bride-to-be, Phaedra, and instead the two journey to Euxine, home of the Amazons.

The people of Athens generally fail to understand the equal and reciprocal relationship that Theseus has with Hippolyta because they see her as a foreign barbarian who does not adopt the traditional female role and because they fear the return of Goddess worship.

However, in addition to losing the greatest love of his life, he has also lost some of the divine inspiration that previously guided him to be the best king that he could be, feeling that he was called to make the sacrifice but that Hippolyta took that from him.

Hippolytos, the son of Theseus and Hippolyta, has grown into a tall, handsome young man with a kingly presence, quiet and serious disposition, and an interest in medicine.

Hippolytus is horrified by Phaedra's overtures and attempts to avoid her at all costs, but, since she confided in him as a doctor, he feels that he cannot betray her thoughts to his father.

Theseus, taken by surprise by these revelations and suffering from the onset of his earthquake warning sickness, exiles his son and curses him, telling him that he will soon feel Poseidon's wrath.

Theseus realises his error and races his chariot after Hippolytus in an effort to reach him, further recognising that his son is the only person he did not warn with respect to the earthquake.

Realising that he should have made her publicly admit her guilt and clear his son's name, he then writes a suicide note in her handwriting in which she confesses to her crime.

An earthquake occurs which Theseus did not anticipate and by that sign he believes that the god Poseidon has truly forsaken him as a punishment for cursing his son instead of warning him.

Eventually, he heals enough to return to Athens where he learns that those in power during his absence have ruined many of his achievements, allowing his kingdom to be broken into pieces and into disarray.

While visiting the king of Skyros, Lykomedes, he sees the young Achilles, who has been hidden on the island to avoid his mother's prophecy that he would die in battle.