Castiel is a marine biologist that reluctantly joins his brother in a search for a mysterious underwater creature. Destiel, Sabriel. Fluff and misunderstandings.

Set after S5 Ep22. Lucifer defeated Michael and Cas joined him. Dean is captured and given to Castiel as a pet. Can Dean change Castiel back to how he used to be or will he give in. Cas/Dean slash, BDSM, master/slave relationship. Really dark.