Bonus Quest: A Gift From the Gods
If you have the AC:O Season Pass, you'll see this bonus mission highlighted in the desert of Saqqara Nome.
Approach the marker to trigger a meteor strike, and begin the mission proper.
Go the impact site as directed, and enter the indicated tomb. Just inside you'll see a large mural of a sundial, with the roman numeral for '15' engraved at the bottom.
The indicated sundial is just northeast of the tomb entrance.
Use your Medjay meditation mojo to wait until dawn. Only then will the pillars around the dial reveal blue crystal contents. The goal of this game is to reach a total of fifteen. The easiest way to get there is to shoot the crystal with five tally marks below it three times.
Return to the tomb and activate the figure there to earn some unique Legendary loot, and complete the mission.
Note that, if you leave the Animus, you'll now find a Moogle plush and a Cactuar statuette in Layla's cavern.