The bathhouse puzzle is an optional side quest in The Pathless. If you choose to complete it, you can earn yourself a PlayStation 4 trophy and more falcon flap crystals to nab yourself extra flight energy. This conundrum is found during the Nimue chapter. You can locate the bathhouse using your spirit mask, so look for the building in the image above to find it. It is best to get airborne to get a literal bird's eye view of its location. Once you are inside, you will spot the giant crystal at the back. To acquire it, you will have to align the three circular targets to thread an arrow through and hit the target on the back wall. Start by walking down the steps to the left of the structure in front of you. Turn on your spirit mask to reveal a circular target inside it. Fire an arrow through so that it hits the target on the other side of the room. Head into the side room that opens. Use your spirit mask again, and command your falcon to drag the target on a ceiling rail to the side room's main area. Once it is in place, head up the stairs to the right. Follow the path around until you fall down. Push a lever to open a door and move the second ceiling-based target to the main area. Fly up to the podium above, and loose an arrow through the targets. Grab the block from the unlocked door. Place the block on one of the pressure pads in the bathhouse's main room. This will lift a target up. Thread an arrow through this target, and the one behind it, to open another door with a block behind it. Grab that block and place it on another pressure pad. The first target will be elevated higher and rotated so that it matches a row of three other targets above you. Fly to a platform over your head and shoot an arrow through these four targets. Head into the room opposite you. A lit torch can now be used to light the other ones dotted around the room. Fly up so that the torch is on your left. Look left and fire an arrow through it to ignite the next torch. Follow the torch pattern around until all of them are ignited. A final block will be presented to you once they are. Place this block on the final pressure paid in the main room. Fly up and fire an arrow through the aligned targets to release the crystal.