The final artifact will be found in the sewer beneath the Tower of Nicholas. Instead of heading through the big metal gate, go across the bridge (next to the sleeping guard) and break down the wall with a nearby sledgehammer. Head into the room behind it to find the Bronze Mirror at the end of the path.

Here are all the codes that are required for locked chests and safes found throughout the Vatican City in Indiana Jones and the Great Circle.

Kick off the recurring "A Remedy for All Discovery" quest by finding every Medicine Bottle in the Vatican of Indiana Jones And The Great Circle.