The Depths is the first Secrets of the Maw chapter DLC of Little Nightmares as well as the second area where you play as the Runaway Kid (who woke up in The Prison). It is located at the very bottom of The Maw and is also where The Granny is encountered.
The Depths appear to have formerly been used for housing as there is several pieces of furniture scattered throughout. However, it is now flooded and may act as sewage or as a ballast system for the Maw. Pipes connect this area to both the Prison and possibly to the Kitchen as scraps of fish are seen being dumped in one of the areas where the Granny lives.
The Runaway Kid's main goal is to traverse through the Depths while avoiding Leeches and the Granny.
After the Runaway Kid wakes up from a nightmare, run to the left until you reach the extreme children's camera. Jump into the hole directly on the bed and run to the right, where you will need to go down the cells. Having run past the Eye, follow the girl with the flashlight. Along the way, you will have to go through the nursery and go down from the Prison window along a rope made of rags. So you get to the room where you will need to jump into the sewer hatch, once in the Depths.
When you find yourself in the water, get out of it using the luggage floating in it. Pick up a flashlight in the next room to further illuminate your path. In the next corridor, the Runaway Kid will be attacked by Leeches, so avoiding them, run to the right and climb up the grate.
When you reach the flooded premises, quickly keep swimming to the right, avoiding the hands of The Granny. With enough time the kid can reach the platform on the other side. Whenever you reach a large drain, jump into it, take any tin can and throw it at the Leeches that have filled the passage into the pipe on the right.
Crawl in the pipe to the end and jump into the water, where you will thus find yourself in a room with a mechanism for raising water. Grab the bars and climb up. Now go to the switch on the left and activate it, and then push the lever in the middle of the room to raise the water level and get into the hole in the wall on the right. There you will swim to the stairs, along which you will climb to another platform. The entrance will be boarded up by boards, so go to the hatch behind the metal barrels and crawl through it.
Then you will again find yourself in a flooded room, where the Runaway Kid will be chased by the Granny for the second time. In order to avoid the floating monster, just like last time, jump on objects until you reach the platform. Climb up the boxes and twist the pulley to pull the bundle of corpses out of the water. Grab it and jump onto the platform made of wood, on which there is a bathtub filled with fish leftovers. Take one of them and throw it into the water to the left, and yourself, while the Granny is eating fish, swim to the right.
In the room you got into, climb on the boxes and push the board onto the rest of the floor, making a bridge out of it. You will reach the door, but to open it, step on the edge of the board in the floor to make it rise. Take a running jump and grab the handle. Open the door and jump to the adjacent platform. With the lever pressed, jump into the water before it completely sinks through the drain hole. So you will find yourself in Granny's apartment.
You will not go through the door on the right, because it is closed, so break the jar on the table to get the key out of it. The Leech sitting with the key will prevent you from completing the task faster, since it will follow the Runaway Kid's movements, so try to be more cunning than her.
In the next room, you need to throw the boxes into the water and make a bridge out of them, but you will have to raise and lower the water level using the button in the wall so as not to die from the current passed through the torn wire. Go through the shower room to the next flooded room, where the Granny will be waiting for you. This time you will have to perform certain actions: first, jumping over the suitcases and barrels, get on the platform in the corner of the wall and throw the fishtail as far as possible to distract Granny, and then swim to the right. Jump over the scattered things until you get into an abandoned room. Jump into the water and climb out to the other side of the room. In the wall, you will notice boards, along which you need to climb onto the broken part of the floor above to pick up the lever. Throw it down and insert it into the opening on the left side. Then press the water drain button and move the luggage closer to you to make it easier to get over the water. The last thing you need to do is open the door with the lever and quickly run towards it before it closes.
In the next room, push the door to get into the last flooded room, where the Runaway Kid starts a boss battle with the Granny. Here you have to swim and climb very quickly to get to the platform successfully. Climb up the gratings and click on the lever to turn on the light in the room. After that, grab the lamp, swing and jump onto the remnants of the floor, barely holding onto a wooden beam. Click on another lever so that water rises in the area, after which the Granny will immediately break the rest of the floor. Climb onto the last wooden platform and push the TV into the water to electrocute the Granny, after which you can safely get out of the Depths.
- When the Runaway Kid is climbing some grates after avoiding the Leeches in the flood, he could hear a scream. This scream most likely is the Janitor's.
- It is unknown why he screamed. However, it is possible that the Janitor pushed a bed to the floor with an Eye to shield the children. This is implied by previously when the Runaway Kid traversed the Prison, no bed is present. However, a bed is present when Six traverses through the same area.
- The Runaway Kid is able to hear a Nome's noises while walking in the drain.