Oh, yes, the title is indeed Intra Profundis. I have it right here in front of me. This is a very new edition, just released two months ago.

And no, I didn't get it from the bookstore. Mrs Brown (she's my foster mother) had it on her bookshelf. This is her own personal copy. I asked Mr Brown if I could bring it with me to Hogwarts, and he said it would be all right.