Caspian and his friends are told that the only way to awaken the three sleeping lords is to sail voluntarily to the end of the world or as close as possible, and to leave behind at least one member of the crew. After the "Dawn Treader" has sailed east for some time in this quest, Aslan appears to Caspian, and informs him that Reepicheep, Edmund, Lucy, and Eustace are to continue on towards the end of the world, but that the other crew members are to go back.