This is a very short case which is available after completing Case 2 A Study In Green
You will be back at Holme's crib and after a cutscene with Orson Wilde, Mary Sutherland will appear.
The case can be solved in 5 minutes without leaving the premises.
There are 3 deductions and any can be used.
You must then make a moral choice o
. Either will unlock the achievement but Holmes does not concern himself with trifling feelings. He is the master of uncovering lies deceipt and dishonestly.
When the case is over you will pop the achievement.