"Professor McGonagall what happened to the heart of the sea?" With a somber look McGonagall answered, "Miss Granger, the heart of the sea was taken away by the Black brothers" Hermione then inquires "You mean killed?" McGonagall shook her head and said, "She was simply taken by somewhere we don't even know to. Regulus back and Sirius black took the heart of the ocean with themselves before they left."