To learn more about the murder in the taste of her sting in Assassin’s Creed: Origins travel to the Shrine of Serapis:
Interact with the corpse on the ground. Go into the cave and interact with the mummy:
Interact with the blood on the table. Exit the cave and climb up to the top. Interact with the symbol on the back of the statue:
Go back towards the cliff and interact with the scroll on the ground.