Path of Light is the ninth chapter of Uncharted 2: Among Thieves.
This chapter takes place almost entirely in one large chamber, where you must position rays of light in the correct direction to lower a series of three blades from the ceiling. Lowering these blades opens access to the next area.
Move the first mirror to reflect light at the face far across the room, then head over to it and insert the Phurba Dagger into its mouth to lower the first of three blades.
Climb up the newly lowered blade, and make your way to the one that's still extended high above the room. Teeter across it and jump to reach the nearby face carving. Climbing up the face reveals an opening where light bursts through for you to make use of soon.
Head down to the nearby walkway and climb down to the level directly below. Chloe positions a mirror across the room from you to reflect light at the one near where you are. Move that mirror to send the light beam into the opening at the bottom of the large object hanging from the ceiling. Head over to the face that's on the same level as you and place the Phurba Dagger into the mouth to lower another blade.
Use the steps that appear as you head towards the ground floor to climb up the blades again. This time, the blade you're on breaks away from underneath you. You must shoot the spot on the face where light seeps through while hanging. While hanging from the green object, move to the left some, then look to the upper left and shoot the small flashing white circle. It will drop down. This is the #36 Carved Jade Figurine Treasure. Climb up the green object and face Drake towards the medium sized mask with the open mouth. Jump towards this mask; it will be a long jump but Drake will make it. After Chloe positions her mirror, run to the left to the mirror and aim it at the green object hanging from the ceiling. Head over to the mask and place the Phurba Dagger in its mouth to lower the final blade.
The giant blade drops into the floor and opens a passageway via the mouth of the giant statue on the floor. Drop in to reach the next area.
As you enter the underground room, insert the Phurba Dagger into the pedestal to reveal a map and end the chapter.