Escape the Mansion Level 99 Walkthrough:
Look at the 3 pictures.
Breathing in = O2 (tap O 2 times).
85% water = H20 (Tap H 2 times, O 1 time).
Breathing out = CO2 (tap C 1 time, O 2 times)
Tap the following elements (letters) for full solution: O O H H O C O O
Proceed to the next Escape the Mansion level!