On this page of our Little Nightmares 2 guide, you'll find a walkthrough description of The Nome's Attic DLC.
The DLC will launch when you get the key in the attic in chapter 1. A mysterious figure will appear that you must run after.
If you want to know how to purchase and start the DLC, take a look at this page: The Nome's Attic DLC - information.
Remember that Six will not follow you. Climb directly behind the character, so you don't let them out of your sight.
As you're climbing higher, you will see a figure hiding from you. You need to find it for it to show you the way forward. All you have to do first is open the case.
Then throw something (e.g. shoe) into a cardboard box.
Your next move will be to open the drawer, right next to the suitcase.
Eventually, the character will hide in an armchair. Just jump on the chair a few times to make it run out, showing you the way forward.
When Nom opens the passage, further run after him to the next part of this floor.
The character will light a match, which will be the only source of light. You must remember that it only moves when it knows you are watching it. So you have to stand in the corner, by the shelves, and then he will move on.
Going forward, Nom will get blocked. You need to move the cart so that it can move on.
Then push the metal door, so that the character can run further over it.
When you reach the next part of the room, Nom will set off the lamp. You can pull the lever that will allow you to move on.
Go back to the room, open the drawer, and run the whole route again.
You will reach a hat that you can get by owning this DLC.
To get out of the room, you simply have to go through a hole in the wall. Eventually, you will appear by Six's side and be able to continue the main storyline.