The Death and Return of Superman (documentary: full video).
Here’s a nice little official video – well it’s actually 45 minutes long, so not so short – from Warner delving into the comic-book roots of that chap in the red cape who sometimes goes around using the moniker of Clark Kent. Yes it’s everything you ever wanted to know about Superman, including his various deaths and many returns.
Do they bring up kryptonite? I’m sure they do.