A Thing

You utter the word "something" very quietly. The man looks at you with wide eyes and replies, "how did you know?" he takes the package back, opens it, turns into a dolphin and dies. The next day you hear on the news that an old man who thinks the word "something" means "I know this package will make me turn into a dolphin and die, and knowing this, I could use it on almost anyone I want. To prevent me from killing people with almost no way to trace the crime back to me, you should sacrifice yourself and open the box instead" has died.