Use the shovel to dislodge the rocks in front of the cave. Then, pick up and read the note inside.

Before you do, use the Harley and head over to the Rennes-le-Bains and the bar. Inside, Gabriel and Mosely are chatting. Grace will talk to them for a few moments, but gain no significant information. When done, open the overhead map and select Blanchefort.

Mount Cardou
Grace will arrive at the Blanchefort parking. Locate the exit toward Mount Cardou and proceed. You'll arrive in an alcove with a few trees and hard mountain rock. There's another note on the tree. Grab the note and read it for some additional clues. Open up your inventory and select the coordinate device. Check the notepad to get the coordinates for the center of the Holy of Holies.

Locate the third clue note at the top of Mount Cardou.

Use the coordinate device on Grace to bring up the coordinate interface. Walk until you are near the coordinates (it's near the back of the alcove). When you reach them, Grace will make an X in the dirt. Open your inventory and use the shovel on the ground. Unfortunately, the mountain rock is too hard to dig into. After you've completed this area, you'll hear the sound of time passing.

Next: Day 3, 12:00 pm, as Grace (cont.)