La obra está estructurada en forma de cortos capítulos, de corte y estilo sobrio y formal, en la que reina más el aspecto figurativo - imaginativo por parte del chico en disputa con el extraño, que el tangible y expuesto. La autora nos narra una historia previsible pero de fondo siniestro parejo a una sirenita sombría.

“Ha llegado un extraño” bebe, indudablemente, de las fuentes Mitológicas clásicas, las leyendas Nacional propias de la ínsula Escocesa, con su folclore, a parte de tener notas de los hermanos Green y sus fábulas. Sin embargo, el viejo Henderson, siempre a cuestas con sus mitos locales, despertará en su nieto Peter la suficiente curiosidad para desconfiar del amable extranjero. Nadie se pregunta porqué él fue el único superviviente de su tripulación. Un extraño naufrago es acogido en la casa de la familia Henderson en Black Ness. Critic Peter Hollindale has gone so far as to assert that Hunter 'is by general consent Scotland's most distinguished modern children's writer.' Her books have been as popular in the United States as in the United Kingdom, and most are still in print. Hunter's portrait hangs in the Scottish National Portrait Gallery, and her papers and manuscripts are preserved in the Scottish National Library.

There has also been great interest in Hunter's views about writing fiction, and she has published two collections of essays and speeches on the subject. Her work, which includes fantasy, historical fiction, and realism, has been widely praised and has won many awards and honors, such as the Carnegie Medal, the Phoenix Award, a Boston Globe - Horn Book Honor Award, and the Scottish Arts Council Award. Mollie Hunter is one of the most popular and influential twentieth-century Scottish writers of fiction for children and young adults. Maureen Mollie Hunter McIlwraith writes under the name Mollie Hunter.

A stranger came ashore by mollie hunter