Then Mac Creiche and Mainchin went west to Inis Locha Ratha Maigi, because Mainchin was his (spiritual) son, and it was he who had baptized him, and had taught him, and was his confessor. They went then westwards to Inis Fide; and Mac Creiche bade Mainchin to place a fetter on his feet; and Mainchin put a fetter on him, as he told him. ‘Give me the key now,’ said Mac Creiche. Mainchin gave him the key; and Mac Creiche hurled it into the mouth of the sea, and vowed that he would never leave the island, till the same key should come to loose the fetter that was on him.