Answer:
Without the string from Ariadne, it would have been very hard for Theseus to escape the maze. "Theseus, take this, she whispered. Even if you kill the Minotaur, you will never find your way out again" (E2BN.org, Commonlit). She requests Theseus to take her with him and she also thinks he will marry her. He doesn't find her attractive and therefore leaves her stranded on an island. "In his haste to get away, Theseus forgot to change his sails to white. King Aegeus, waiting on the headland, saw the ship approaching with its black sails flying in the wind"(E2BN.org, Commonlit).