Call of Cthulhu Advice

I was recently asked for some advice from a younger Call of Cthulhu Keeper who wishes to introduce the game to newcomers to both the game and Lovecraft: what adventure would I recommend as a good introduction to it? That's when I realized that I haven't played Call of Cthulhu in more than a decade, unless you count Delta Green, which I don't. Consequently, I don't have any good answers to this question. However, I suspect many of my readers might. 

So, if you were going to introduce new players to Call of Cthulhu, what adventure would you use? Bonus points if the scenario can be reasonably completed in two 4-hour sessions or less. It can be for any edition of the game or any publisher. Just don't say "The Haunting," because, much as I like it, I don't think it's all that representative of what Call of Cthulhu is about.

Thanks!