Where the World Ends is set on the island of St. Kilda, off the coast of Scotland. A group of boys and three adult men are delivered to Warrior stac, which is less of an island and more of a rock (featured on the book cover) jutting out of the ocean. On the stac, the boys and men are meant to harvest the local birds for profit. This includes killing gannet, puffin, and garefowl for meat and for the oil in the birds' stomachs, which they will sell when they are picked up and returned to the main island. This is how the people of the St. Kilda archipelagos make a living. However, this time, no one comes to pick them up.