A Death Note is a notebook that magically kills anyone whose name is written in it, by a heart attack after 40 seconds, if the writer has the face of the victim in mind. Suppose a god of death left a Death Note on the ground, and you happen to find it. Nobody knows about it but you. Would you use it? If so, how? If not, what would you do with it?
For this thought experiment, we can ignore all the further complexities of the anime series.