Michael and Mina are clearly the main characters of this excellent novel, as it is they who care for Skellig and are part of his resurrection. Michael is a ten year old boy who has been made solemn and serious by life, and is clearly juxtaposed with the carefree Leakey and Coot, who are shown to live a life that is free from responsibility and characetrised by joy. The turning point in Michael's life comes because of his sister and the possibility that she might die. This is something that turns him into a serious and anxious boy who has to reassure himself that his baby sister is still living by going into his parents' bedroom at night and touching her hair and skin.
Mina couldn't be more different from Michael. She lives just down the lane from him and is very self-confident. Her significance comes from the way that her friendship with Michael contributes to his blossoming, in particular concerning her observations about nature and the wonders that go on around them. She is homeschooled, and as a result attacks the traditional school system, saying that it stifles and detracts from exploring interests, such as her interest in William Blake. She regards Skellig with an eye for analysis, believing that he may represent an evolutionary phase between man and the ability to fly, but her scientific stance does not prevent her from being open to the wonder of what these children experience. Just as Michael gains a wider vision on life from Mina, so Mina is encouraged by Michael's openness to move from merely observing life to actually living and experiencing it.