-MISSABLE-Note:
Only obtainable with the playable character
Chris Redfield.
Later on in the game when you return from the Residence where you fought Plant 42 a cutscene will introduce the infamous Hunters. At one point you will aquire the
EMBLEM KEY which opens only one door. This key looks different than the other ones. You have to find a
Jewelry Box and combine it with a
Red Gemstone to obtain it. The office in the
1F EAST WING of the Spencer Mansion can be opened with that.
As soon as you enter that office a short cutscene appears showing Chris notice Rebecca screaming. Now is the time to make your way up ASAP. Exit the office, use the door to your left leading to the save-room, go upstairs, turn right and enter the only accessible door of the two. Take another right and enter the room. A cutscene makes clear the Hunter is about to kill Rebecca. Make sure he's not and get rid of him by any means necessary.
The achievement should unlock right after the happy rescue scene.
Hope this helps. Let me know if I should add anything to improve this solution!
