Theseus and Aigeus wage war against the Pallantids for over a month, destroying their enemies and gaining much land and wealth. Theseus listens to advice from his father and uses it in ruling Eleusis, although he sometimes goes against it. He suggests that Aigeus unify the laws in Athens, but his father wants to let the people rejoice and not have any more trouble. Theseus thinks that eventually he will have to deal with the problems in the kingdom his father does not fix. Winter passes into spring, and Aigeus realizes that he must throw a feast for Theseus' birth month. He gives his son a chariot with fine horses, and they plan to take them out. Theseus waits for his father, but when Aigeus comes he says he may not go along. Theseus asks why, but is not given a reason. A man comes in and tells the King that the Cretan Captain is waiting on him for the lottery to choose the fourteen bull-dancers. Theseus immediately tells his father it would have been foolish for him not to be there, and says he must send his Companions home so they are not walking around while Athenian youths are chosen. The King tells him that the Companions were rounded up with the rest. Theseus is angered, and his father tells him that the Cretans will not let them be separated. He suggests that one of the Companions should be chosen. Theseus is enraged, and says he swore to protect them. He decides that he must go and take his chances in the lottery like everyone else if he cannot get the Companions out.
Theseus goes over to the Cretan Captain and talks to him, and learns that the Captain does not care about the Companions or his kingdom but does not want a riot when certain youths are taken out of the line. Theseus then says so all can hear that he is joining the lottery. Aigeus invokes the gods, the lottery begins, and the maidens, all virgins, are drawn first. Next the youths go, and one of the Companions, Menesthes, is drawn. Theseus looks at his father and realizes that his father is not worried. He understands that his father wrote someone else's name on his lot. Meanwhile, Amyntor, another Eleusinian, is called. Theseus knows that Poseidon has been wronged, and he drops to one knee to ask the god what he must do. He realizes that he must choose whether he is the son of Aigeus or the son of Poseidon. Theseus looks back on his life and sees clearly what he must do. With his spirits high, he volunteers to take the place of the last boy, whose lot had just been called. His father tries to convince him not to, but Theseus is firm and tells him the god gave him the message. Aigeus tells him if he ever returns that he should "paint the sail of his ship with white" so that he can know when the god has a message for him. Theseus leaves, knowing his father never expects to see him again.
Theseus volunteers to go to Crete and be a bull-dancer, an occupation that every youth fears. He does so because he knows that it is what Poseidon wants. Theseus has never gone wrong following the god, and so he decides that he must trust in a higher power. His actions are brave and noble, but it would be better for all of Athens if he did not go to Crete. There was a small chance that Theseus would be chosen, but his father attempts to make Theseus's selection impossible. Theseus's decision to volunteer proves that it is impossible to challenge fate. Although Aigeus did everything possible to make sure that Theseus would not go to Crete, he ended up going anyway. Theseus, who knows that he cannot ever be fully in control or able to predict his life, is content to go wherever the god sends him. Aigeus, on the other hand, after many years finally has a son, someone he can entrust his kingdom to after he dies to make sure that all of his work does not end with him. Theseus knows that he will do what the god asks, and that Aigeus would willingly sacrifice himself if the god called.
The gods can be refused, as Aigeus demonstrates when he does not let Theseus drink the poisoned wine. However, a refusal of the gods constitutes thwarting justice. The Eleusinians never receive just compensation for the wrongs that the Athenian king, Aigeus' grandfather, did them, and the curse of the Mother is an appeal for that justice. In the same way, Aigeus attempted to unfairly exempt Theseus from the lottery, and Poseidon's requests justice. Theseus has lived his life according to that call, always attempting to mete out justice and follow the righteous path in his dealings with friends and enemies alike. He knows that what the god asks him to do is what should be done. Therefore, when he volunteers to take the place of the last boy, he does so not with a heavy heart but with his mind at ease. For Theseus, the contentment that comes from doing the right thing is worth the grave personal danger that comes with that thing. That quality makes Theseus an admirable character, and because he is willing to do the right thing regardless of the dangers he inspires courage in others as well as tremendous loyalty.