After the business with the train, once you board the ship, and after plot things happen (the baroness is murdered), then this achievement will be available.

It's important that you get ICE TONGS from the saloon bar before entering the baroness's room.

If you go into the saloon and don't see the captain and the ice tongs, try talking to Inspector Legrande below deck.

Then, SAVE before you enter the baroness' room on the ship in chapter 1.

While you're in the cabin, ALWAYS start with RIGHT clicking things before you left click to examine.

And DO NOT leave the room as Zellner insinuates you should do. Just examine everything several times in one go.

Also, due to a bug, you must get the feathers from under the bed before getting the feathers from the vase.

• Portholes
  
• Luggage
  
• Handbag x 2
  
• Diary
  
• Painting
  
• Mannequin
  
• Cupboard
  
• Tape Recorder
  
• Audio Tape Reel
  
• Fire Alarm
  
• Vent cover on the ceiling by the door
  
• Portable Cupboard
  
• Bed & Blood Spot
  
• Under Bed for feathers 1/2 (you MUST get these feathers before the feathers from the vase)
  
• Vase - and vase again last time
  
• Get feathers 2/2 next to vase
  
• Notepad
  
• Lock & Chain on door (right click then left click)

It's not necessary to open the cupboard by the door. I got the achievement without it.

When you're done, the only thing left to interact with will be the spot on the bed.