
Use the last three Power Cells, and this time, a panel on the left will show angle measurements (90 degrees, 270 degrees, etc). The first door is open, and on the right of the new room, you will find five more holographic locks. Imagine each hologram as a clock and turn them to their respective position.

A display to the right will show five 24-hour codes in military time. Now you have to solve a puzzle where you have to rotate each of the five holograms into a certain position. Take your five Power Cells back and slide two into the vacant slots. The Power Cell sits on a shelf to the right at the very back. There are hidden handholds leading up to a hidden-in-plain-sight area where you will find a purple-lit hallway. Instead of rappelling down, go to the left of the rappel point and carefully move to the edge of the cliff. The final Power Cell requires the quest The Mountain That Fell. You will need to pass this cell in order to get to the next part of the facility, so it is perhaps the most difficult one to miss. Once you have restored power to the Ancient Door and gone through it, look around until you spot a telltale green diamond, indicating the hidden Power Cell. The fourth cell is in the Grave-Hoard, where you will go to as part of the Grave-Hoard main storyline quest. Use the rappel point to return to Ted Faro's office and continue the quest. Follow these all the way to the top and find the Power Cell there. Once there, instead of following the quest objective and examining the data storage system, turn around and find the yellow handholds leading up the ruined sky scraper. Climb all the way to the very top of the ruins to Ted Faro's office. The third cell is in the Maker's End ruin, which you will visit as part of the Maker's End main quest. Note that the fifth and final cell cannot be obtained until the quest after The Heart of the Nora in any case, so this makes little difference overall. The gate to Mother's Watch will be closed and All-Mother cannot be entered until then. If this Cell is not obtained during the Womb of the Mountain quest, it will not be accessible again until the main quest, The Heart of the Nora. Look to the left, crawl down a tunnel lit with candles, and you will find the Cell in the room at the end. Instead of following Teersa to the left, go straight out of the room where you get your equipment back until you find a locked red door. After the Proving quest, you will end up here at the beginning of the main quest, The Womb of the Mountain. The second Power Cell is in All-Mother Mountain. Simply smash these with your spear and you will find the Power Cell on a table at the back of the room. Beyond that there will be another doorway which is blocked by stalactites. Eventually you will come to a locked door that must be pried open with your spear. Return to the ruins near Mother's Watch and make your way through them. This location can be revisited at any time during the game.

One Power Cell is found in the underground facility that Aloy fell into as a child. Horizon: Zero Dawn - The Frozen Wilds Review The first Power Cell can be obtained during The Womb of the Mountain. Four of the Power Cells can easily be obtained during the main quest, but the fifth requires Aloy to revisit the ruins she fell into and found her Focus in as a child.
