We’ve escaped the schoolchildren, for now, but that only means we’re bound for another run-in with the teacher.

After escaping the cafeteria and hallway full of wooden schoolchildren, you’ll enter a room with a button. There is a glass bottle on the floor, but that’s not strong enough to throw against the button to open it. You’ll have to find something else.

Go to the background with the shelves.

Ascend the shelves until you see a wooden plank on a light fixture.

Cross the wooden plank and jump onto the shelf to the right.

You’ll see a rope you can swing from to the left. Jump onto it and onto the shelf with the brain jar and a hook to the right.

Throw the brain jar to the ground (don’t worry, you have to break the jar) and ride the hook safely to the ground.

Now that the brain is exposed pick it up and throw it at the door to open it.

Cross through the small room into the next area.

The teacher will be in this room, but she won’t see you as long as you stay hidden. She’ll eventually move into the next room to the right.

Take your time moving through the science lab. As long as you stay behind objects, she won’t see you when she turns around. You’ll have to time the teacher turning around before moving to the next block of objects to obscure her vision.

Don’t rush through this part because you’ll have to start all the way back from the beginning of the science lab, so wait until the teacher turns around, and jump from the science table to the opening.

You’ll emerge into a hallway. Climb up the bookshelf and into the vent.
Where do you go next? Find out in Little Nightmares II School Walkthrough Guide – Part Seventeen.
If you’re stuck on the Little Nightmares 2 game, you can refer to these walkthrough guides for help:
Little Nightmares II: Gameplay Walkthrough Guide – Part Eleven
Little Nightmares II: Gameplay Walkthrough Guide – Part Twelve
Little Nightmares II: Gameplay Walkthrough Guide – Part Thirteen
Little Nightmares II: Gameplay Walkthrough Guide – Part Fourteen
Little Nightmares II: Gameplay Walkthrough Guide – Part Fifteen
Little Nightmares II: Gameplay Walkthrough Guide – Part Sixteen
Little Nightmares II: Gameplay Walkthrough Guide – Part Seventeen
Little Nightmares II: Gameplay Walkthrough Guide – Part Eighteen
Little Nightmares II: Gameplay Walkthrough Guide – Part Nineteen
Little Nightmares II: Gameplay Walkthrough Guide – Part Twenty
Little Nightmares II: Gameplay Walkthrough Guide – Part Twenty-One