Scrub the family portrait in the kitchen with the brush.
Official in-game clue: "There is blood and what else? This drawing is helpful but…"
Where: Day 2 Afternoon, during the Cleaning the Floors block.
Why it gets missed
You are told to clean the floors, so you clean the floors. The achievement is somewhere else in the room entirely.
The clue is unusually oblique even by this game's standards. There is blood and what else? reads like it is describing the floor you were sent to scrub. It is not — it is describing the portrait, and the trailing this drawing is helpful but… is the part that gives it away.
What to do
- Take the brush you were given for the floors.
- Use it on the family portrait hanging in the kitchen.
- Keep going until it is clean.
Then finish the actual chore. Doing this first does not stop the floors from being cleanable afterwards.
While you are on Day 2
Two other achievements in this day are lost by doing the job properly the first time: the coffee wants the beans roasted and ground, and the feather belongs on William's face rather than his feet.
Nearby
The full list of hidden achievements, in the order you reach them, is on the triggers page. Going for everything in one run? See 100% completion.