When Sauron's stronghold fell he escaped by inhabiting the body of an injured kitten belonging to the kitchen cat. Maglor who was freed from the stronghold when it fell sees the kitten and saves it. The Valar transport them to an island so that Maglor can learn to live and come to terms with being free again. He finds love in the form of a former king of Middle-earth and makes friends with the mermaids while lobster fishing.
Sauron remains as a kitten, he dare not change back and is incensed that Maglor has named him Glorfindel after his liberator. He is even more angry when Maglor falls in love. What will Sauron do?
And what about the little black kitten that turns up halfway through the story? Who is he really inside and why does Sauron call him Master?