Ray of Light

The locket wasn't the only thing Miner wanted in exchange for the Monolith shard. He also wants two flashlights to get used to light again. He sends you to Akim for them.
== Walkthrough ==
Talk to Akim. He won't give you flashlights for free, you have to complete Rubick's cube for him. After doing this, you'll get the location of a stash with flashlights - it's inside the elevator shaft in X-16 laboratory (15:18 on the video below).
After taking the stash contents, an underground tremor will throw you off the catwalks to the bottom of the shaft, so you'll have to exit the lab the other way alongside fighting a gauntlet of enemies (to the tunnels) since the ladder in the shaft is located too high to be able to climb it back. However, if you're fast, you can actually break the fall by maneuvering in the air onto the catwalks below.
Bring the flashlights to Miner, and receive your shard of the Monolith - Poltergeist's Heart - back.
== Notes ==
* As you probably remember from Cave dream, Poltergeist's Heart is powerful but extremely radioactive (+85Ci), and you need plenty of other artifacts to counter the radiation poisoning.
* Be wary of the mutant gauntlet once you grab the stash and fall to your doom, especially the controllers in the Brain room, where you will need automatic targeting from your binoculars or guns like the AWP "Antikiller" or the FN2000 "Executioner" to find the controllers. 
== Bugs ==
* The falling cutscene triggers as soon as you have both flashlights in your inventory. If you take them out and drag one by one to another location and take them both, then the cutscene will trigger in that location: the ground will shake and you will be teleported to the XYZ coordinates where the fall is supposed to happen. Since these coordinates are applied to another location than X-16, you'll be likely teleported underground.