After completing Snake in the Grass, head back to the Sanctuary of Delphi. Herodotos is waiting behind the temple in front of two columns that look like they have snakes coiled around them.

Upon arrival, a cutscene will begin. The player's character will put on the cultist robes from the last mission and head into the cave. Walk down to the bottom, there are no enemies to kill here.

At the bottom of the path, it's time to investigate and gather information. Look for these clues and initiate conversations with:

The cultist at the pedestal

The two cultists arguing about the next target

The notes in the room behind the waterfall

The cultist torturing the other in the room beyond the rocky path to the northwest

Once all the clues have been found, return to the center of the room and place the fragment collected in the last mission on the glowing orange pyramid in the room. A cutscene will play, showing the real identity of Deimos and his violent nature.

A conversation with Herodotos rounds out this mission. None of the choices will have long-term consequences. Once this conversation has ended, the mission will be complete.