Narcissa wanted to rip the locket out of his hands but she knew better. Kreacher was not her elf, his loyalty was merely to the Black bloodline. It would be easy for him to hurt her or never return if she tried something drastic. She also knew how insanely obsessive he could be when it came to her late cousin... She took a deep breath and said... "I understand... but you must do exactly as I say..." Kreacher looked at her with wide football like eyes listening intently "Take this right now and go to Professor Snape. You can appear before him only when he is alone... Tell him that I have sent you and that he must show you how to destroy this... Apart from professor Snape you speak to no one about this locket ever!"