999: Nine Hours, Nine Persons, Nine Doors/Door 8
 Laboratory (C Deck)
Turn right and tap on the lockers with the green light on them to zoom in. Tap them again to open the middle one, and click on the item inside to get ethanol. Look down and right, then click on the shelf to the right of the counter to get 3-pronged power cable. Look left and click on the monitor on the right while holding 3-pronged power cable. Look down and turn left twice, then tap on the window.
Click to examine the large table in the bottom right, then the square computer in between the table with the mannequin and the large computer on the wall. Look down and right, then click on the metal bars twice to get 2-prong plug. Combine it with 3-pronged power cable to get 2-pronged power cable. Hold ethanol and tap the bars again. Look down and left, then tap the window. Examine the table from before, in the bottom right, three times. Look down and to the right and click on the bars twice to get a new file.
Look down and to the right and examine the computer. Click on the monitor while holding 2-pronged power cable to start it up. A puzzle will show up on the screen. There are nine squares, all either red or green, you have to get them all green in four clicks. When you tap a square, that square, as well as the ones surrounding it, change color. The file you got from clover is the solution to the puzzle, but you don’t have to tap the squares in a particular order for it to work. Just tap the middle square and all the corners except for the bottom left one.
Tap down and examine the newly-unlocked right set of nine lockers . Click them again to open them, and grab the items inside to get the Earth key as well as activation key. Turn right twice and examine the computer on the counter on the left. Click on the red square next to the monitor while holding activation key. Look down, turn right twice, and examine the window. Click on the big computer on the far wall, on the right side, twice. Look down and to the left, and click on the right door. Then click on the left door to escape.
 Room Choice
After some plot advancement, you will get to choose what door you want to go through. This decision will have an effect on the ending, and you won’t be able to go through the other door in the same playthrough.
- If you go through Door 1, you will be accompanied by Ace and Clover.
- If you go through Door 2, you will be accompanied by Seven and Lotus.
- If you go through Door 6, you will be accompanied by Ace, Santa, and June.
If you are trying to get a particular ending, check the Endings page to help you choose.
Also, to continue this walkthrough, be sure to go to the page of the door you go through, and not just the next one on the list, as the chronological and numerical order of the doors is different.