Exotic Matter Laboratory
Fuse
Held by the claw of a small crane over the assembly line. It goes in the fuse slot of a door about 19 m away and 7 m lower.
What it is for
Where the walkthrough uses it
3-2 The Assembly Line· step 1both players
Get the fuse from the small crane over the hall. The Goop Gun player goops the fan in the north wall. While the Hook Gun player hooks it aside, the Goop Gun player climbs into the duct behind it, follows it to the east catwalk and holds the crane chain down. The Hook Gun player hooks the fuse from the hall floor under it and puts it in the slot by the fuse door: the door opens. Going for Many Ways? Leave the fuse on the crane.
3-2 The Assembly Line· step 4both players
Both of you stand on the lift and pull its two-handled chain: Onwards and Upwards unlocks. If the fuse is not in its slot at that moment, Many Ways unlocks too.
Where to find it
No item spot is random: the game files place every item in the same spot in every game. Some items exist several times at once, such as the fuses in the Time Maze. From the game files: the area is loaded at these checkpoints. A door on the way can still be locked at some of them.
How to find it
Held in the claw of the small crane above the conveyor belt. Pulling and holding the crane chain on the east catwalk lowers the crane; the fuse can then be hooked from the hall floor right under it.
Checkpoints where its area is loaded
- 3-2 The Assembly Line · both players
5 mSeen from above with the ceiling removed. Yellow ring: this spot. Small labels: other spots of the same item close by (select one to go to it). 
The spot seen from nearby (rendered from the game's own level geometry).
Achievements

Many Ways Missable
Activated the Cargo Elevator without using a Fuse
Start the cargo elevator (both of you on it, chain pulled all the way) while the fuse slot at the fuse door is empty. Never put the fuse in: it locks in place and the door stays open. Without the fuse door, the Hook Gun player gets up to the gallery for the green key over a goop stair on the lift floor, through the gap in the rail above the lift gate. The Cargo Elevator page has the whole route.

Onwards and Upwards
Activated the Cargo Elevator
How it unlocks (spoiler)
Both of you stand on the cargo elevator (3-2 The Assembly Line), then pull its chain all the way.
Items:
Green key
Purple key
Could not find one, or something here is wrong in your game? Tell us and we will check it. Report a problem