This mission was made in the 6th Version of DYOM, you can get it in GTA Garage, it's a storyline mission, it's not long, 4 small missions in one storyline, can be done in around 10 minutes.

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Carlo's Secret Treasure - 6# - Salviati's Trail

The next Conspirator, Salviati, is holding the most dangerous Sacred Page, it allows him to order people like mere puppuets.
Leonardo will have to Eavesdrop and save citizens in order to collect information about Salviati Janitierri, his next target.