Just as Indy and Sophie get to fabled Atlantis, they find themselves in the clutches of those dastardly Nazis! With Indy in yet another tight fix, he turns to Sophie for some advice but unfortunately she has gone completely `round the bend, as a strange Atlantean spirit has taken control of her soul. Meanwhile, the Nazis are getting closer to reaching their goal and achieving god-like powers! It doesn't get any better than this, kids!
This is related to the videogame of the same name. Preliminary research indicates that this was published prior to the videogame, but given the lead-time on videogame development, it's quite probable that the story originated with the videogame team, led by writers George Lucas, Hal Barwood and Noah Falstein.