This may be the most overrated of the so-called classic adventures for (A)D&D. An unfinished mess, much of it is the product of Gygax's latest attempt at random dungeon generation. And a big chunk of it - the elemental nodes - are there for the individual DM to complete. For something that says "elemental evil" in the title, it's amazing how little "elemental evil" has to do with the product that follows. If you're going to run it, prepare to do a lot of work to make it work. Better yet, write your own. Note that any DM or player who tells you how good this adventure is will then tell you that the DM did the work to make it an excellent adventure. As written, it's just an unfinished mess.