Enter the new location and jump down, to a lower level. Follow the path across this location and pick up the Scroll Holder - 4G along your path. Squeeze through the narrow passage and, right after you walk onto the pressure plate, locate the button that disables all of the taps. You can now open the nearby door and walk into the main part of the ruins [Underground Ruins - Forgotten Ruins].
Find another Scroll Holder - 4G here, and start by examining the Northern door, which you need to open with lockpicks. Walk along the narrow corridors. After you enter the last corridor, examine the four new symbols on the side walls. Approach the podium then and solve the puzzle identical with the one that you have already solved. The solution is in the above screenshot. For solving the puzzle, you will be rewarded with the unique figurine (Unique Loot - Ancient Figurine).
Return to the main are in the ruins and locate the button that disables all of the traps in the area. Only after you press it, go West. After you walk into a round hall, walk through the smashed stained glass window. You now need to reach the lowest level in this location and you can get there by climbing down the stairs, or by taking a turn to the right ate the first opportunity and jump towards the rope, over which Garrett can climb down. In general, this does not matter which path you take. Proceed across the ruins, look around for the desk with a locked drawer, where you will find a Scroll Holder - 4G. The next location in Garrett's path is the [Underground Ruins - Scriptorum] and you can reach there by taking the upper or the bottom passage.