What Lies Below is the name of Chapter 16 in Dead Space 3, the video game, and it is rather a short mission, that doesn’t include many collectibles to be found.
After Danik manages to get the Codex in Chapter 15, it is Isaac’s job to follow him through a giant hole that leads to the Machine, because he must stop him from powering down the Machine at all costs.
The following videogame guide features the locations of all Dead Space 3 Chapter 16 collectibles, and it should be used as presented below, if players want to achieve a 100% completion rate in a single playthrough.
Mission Description
Underground Descent Tau Volantis secret is revealed: the Machine wasnt created to start Convergence it was created to stop it. The aliens built the Machine to freeze the true enemy: the Necromorph moon. Isaac must now stop Danik from shutting down the Machine.
Collectibles Guide
Hidden collectibles available: 7
Logs: 1
Weapon Parts: 4
Circuits: 1
Blueprints: 1
Weapon Part #1 (S.C.A.F. Frame)
First, you need to use a device to rappel down, and then you have to take the elevator.
Before using the device to rappel for a second time, you check the end of the path (next to the climbing machine) for the first Dead Space 3 Chapter 16 Weapon Part.

Weapon Part #2 (Rail Accelerator)
Next, during your second descent using the rappel device, near the end, you have to pay attention on your right side, because there is a small platform where you can find the second Dead Space 3 Chapter 16 Weapon Part.
You use Kinesis in order to grab it, but make sure you have one free slot in your inventory.

Weapon Part #3 (Safety Guard)
When youre done rappelling, you enter the first shack and you look immediately on your left side.
On top of the shelf there is the third Dead Space 3 Chapter 16 Weapon Part.

Log #1 (Audio Log)
Next, you hack the door, and as you enter, you can find the only Dead Space 3 Chapter 16 Log on the desk next to the suit kiosk.

Circuit #1 (+2 Damage +1 Clip)
When you head outside the room with the bench and suit kiosk, you have to look behind the left corner (near the exit door) to find a circuit box on the wall.
Inside is the first and only Dead Space 3 Chapter 16 Circuit.

Blueprint #1 (Javelin Gun)
After you use the rappel device for the third time, you defeat the strange Necromorph, and as you follow the path you look below the scaffolding in order to find the Dead Space 3 Chapter 16 Blueprint.

Weapon Part #4 (Heavy Standard Frame)
Next to the Blueprint is an ice sample, and on top of that sample is the fourth Dead Space 3 Chapter 16 Weapon Part.
Now you just have to rappel down for the last time to reach the Alien Ruins and trigger Chapter 17.
