A mysterious stranger shows up at Barnett College with an ancient key, and Dr. Jones puts down his grade book to go in search of his former archaeological colleague, Sophia Hapgood. Now a trendy psychic, "Madame Sophia" is doing very well for herself by fleecing people out of their hard-earned money. Toss in a tiny minotaur-like statuette, sprinkle in a few overzealous Nazis, and cue the music!
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.