How to Beat Fumus (Red-Circles Boss)

Fumus is the second boss, fought in the candlelit area after Floor 1, reached through the Animal Skull Key door. Fumus summons red circles on the ground that punish whichever weapon you hold:

• holding a loaded firearm and stepping into a circle triggers instant death (suicide)
• holding a melee weapon causes self-harm
• holding an unloaded weapon triggers a long animation that drains you

1. Unequip everything before the red circles start.
2. Run straight into the circles so they vanish.
3. Counter-attack while Fumus is staggered.

The strategy is the same in every reload — the only safe answer is to engage the circles empty-handed.

Defeating Fumus using only the Iron Pipe earns the missable Exhaust Pipe achievement. The Pipe must be picked up from the bathroom using the Screwdriver (Classics Never Die achievement is also missable). This run invalidates the Wrench Queen run because it requires the Pipe for Fumus instead of the Wrench.

The Pipe pickup and why holding it changes the red-circle logic are on the Iron Pipe weapon page. For the conflict between Exhaust Pipe and Wrench Queen, see combat strategy and the achievements checklist.