No drama, I'll take you straight to the spot.

Select the level "Tower"

1 - Grab the blue key from the top of the fountain in the first room.



2 - Use the blue key on the double doors to "Geometry Cache"



3 - Grab the red key from the desk on the balcony.



4 - Head just below to the gift shop "Swords & Spiders", which you passed on the way up. Use the red key on the doors.


5 - In the display case is the green key, take it.



6 - Head over to "Imports" with the green key and use it on the door.


7 - Head up 2 flights of stairs. At the top is the module. Just below you, is the reclamation bin.


Cheers!