The Fieldwork missions in Indiana Jones and the Great Circle are optional side quests in which Indy can help people in need, ...

Doing that gets you the Indiana Jones Cloud Atlas code 0609. Using that code to get the Cloud Atlas chest open gets you ₤50, a map showing all the Gizeh medicine locations, and 225 Adventure Points.

The Indiana Jones Secret of Secrets safe is found around the back of the Sistine Chapel, shown on the map above. In the room with the safe you'll find a note explaining that Father Nicoletti found ...