The Final Voyage Of The Mary Celeste
... the ship is found, abandoned, its cargo untouched. The crew is never found. Over the years, many bizarre theories have arisen to explain what happened on that fateful night, from aliens, to sea monsters, to time travelers... But what if they were all true?
Now available in a pro-quality ebook, free, as seen on this RPGnet thread. Nice, con-friendly, just about ready to run if you have a couple folks spare.