Samiadon possesses a notoriously grumpy and lazy disposition, distinct from typical mischievous genie portrayals. Its core magical ability allows it to grant one wish per day to the children who find it. However, any magic resulting from these wishes invariably disappears at sunset, restoring conditions to normal.

Residing in an abandoned lime quarry in England during the mid-1980s, Samiadon is discovered by four children: the siblings Cyril, Robert, and Jane, along with their neighbor Anne. The story unfolds through their daily wishes and the complications that arise, which consistently resolve by sunset due to the magic's limitation.