Lord Donnán (pronounced Dun-an) is the regent of Éilís Mór. He has a son, Kieran Donnán, who went missing just prior to Wakefield's arrival on the island. When strangers visit the island, they are supposed to check in at his mansion. When Wakefield arrives on Éilís Mór, he receives a letter from a man with a invitation to meet Donnán at his mansion. Donnán Manor has a large collection of pagan and roman artefacts. Including an ancient roman statue and a carpet with the serpent sentinel.
Donnán knows a lot of the pagan tales regarding Éilís Mór. Wakefield arrives at Éilís Mór around the time the Festival of Reunion starts. The reunion is a pagan halloweenesque ritual where villagers dress up like animals or monsters in order to not be noticed by monsters and ghosts who haunt the village during this time of the year.
When Wakefield compliments Donnán on his vast knowledge about the folklore of Éilís Mór, Donnán states he knows just a little. He tells the doctor that he should talk with Miss Foster, the teacher in Éilís Mór's school. She has even more knowledge about the folklore of the island. She tells Wakefield Donnán's son Kieran is missing.
Wakefield learns that Donnán is actually quite xenophobic from the Lighthouse keeper.