XON Episode Four walkthrough
XON Episode Four is a puzzle-exploration game. The player needs to first understand what he should do and only then - how should he do it.
Tip: If you are stuck because of a bug, go to the game menu and tap 10 times on the XON logo. You will be teleported to the starting area so you can continue playing.

Before reading the whole walkthrough, here are some hints to set you in the right direction.
Orange crystals: There are 40 orange crystals in the game. Collecting them is optional.
This is the map room, the map inside will show you the location of all of the orange crystals. Note that you can finish the game without collecting the orange crystals.
This is the gallery. You will need information from the gallery to solve some of the puzzles.
To open the map room, use info from the gallery and this statues:
This is a tram station. One tap on the blue button will open the tram, second tap will call the tram to the station. If the tram doesn't arrive, it is blocked by a closed stations.
White crystals: there are five of them in the game, you must collect all five to finish the game.
To open the big doors, use these viewers to collect light energy:

Inner Area
This is the temple.
Use the floating statue and the symbols in the three stone passages to get three symbols and open the lower black "flower".
You can get to the stone passages by going up this maze. You will also find a white crystal on the maze.
Use the symbols you found in the temple to go through this maze and get another white crystal.

Lake Area
Use info from the gallery to solve the maze puzzle and open the black vault with the white crystal.
Once you have five white crystals, use the temple elevator do go to the lower level, solve the cylinder maze and insert the crystals into the device...

Full Solution

Opening the big doors
To open the big doors you need to focus light energy using the yellow viewers to the yellow totem.
Collect two blue crystals from these crystal holders:
And insert them to the viewer. Next, tap on the dark area below the crystal to enter the viewer.
Use the arrows to rotate your view left and right or to move the view up or down. You need to center the view on a blue gem on the totem. When you do - the view will become brighter and you can exit the viewer by tapping the middle of the screen.
Once all three of the light rays are hitting the totem, the doors will open.

The Gallery
This is the gallery. It contains important information for solving some of the puzzles. You can also pass through it to get to the inner area but only after you opened its inner door.

Orange Crystals
The orange crystals are scattered around the game. There are 40 of them in total. This is optional - you don't have to find them to finish the game. This is the map room, it contains a map with the location of all of the orange and white crystals in the game. Orange crystals are marked with an orange hexagon and white crystals are marked with a gray circle. Once you pick a crystal, its sign will disappear in the map room.
To open the map room, you need on three of the symbols on it's base. To find out which symbols to tap, use this diagram from the gallery:
Go to the three colored statues. Around them are six white pedestals with symbols on them. The diagram from the gallery shows you three views of the statues from three of the six pedestals. Find the correct pedestals matching the views in the diagram and use the screenshot feature in the game's menu to photograph the symbols on these pedestals. Go back to the map room and tap on the three correct symbols to open it.
Click here to see the correct symbols.

White Crystals
There are five white crystals in the game, you can find them inside black vaults. You must find and collect all five of them to finish the game.

Inner area
Enter the big doors. The big reflective structure is the temple.
Inside the temple you can see three stone passages. You will need to reach them from the outside.
Exit the temple and go left. You will see a big 3D maze. Use the three small blue columns to move the three big columns up and down.
The big columns have openings in them to enable you to path through. Align them with the stone walkways to create a pathway. First, you should create a path to the temple. In the stone passage entering the temple you will see two symbols on the wall, use the screenshot feature in the menu to photograph them, you will need them later. Tap the blue button on the ground.
The ring elevator will come up. On the elevator you will see symbols and sets of two buttons that change color from black to blue and back. The buttons are for moving the elevator up and down. They turn black once you cant go up or down anymore.
Now go back to the 3D maze. There's a white crystal on the maze. Locate it and create a path to it.
Go down to the beginning of the maze and create a path to the opening in the cliff side.
Inside you will find another maze. Use the buttons on the consoles to move the columns up and down. Create a pathway that ends where the orange crystal is.
Start with the column closest to the end near the orange crystal and go back until the maze reaches the floor and you can climb in.
Once you're up, go through the stone passage, take a screenshot of the two symbols and call the elevator with the blue button. You're now on the highest floor. Use the elevator to go down to the first floor and get in the stone passage to get the last two symbols. You can see a small garden with three orange crystals from this passage, you will open it later.

Floating Statue
In the middle of the temple there's a black floating statue. You need to use it to open the black "flower" below it.
The symbols you collected from the passage indicate the floor (left symbol when coming into the temple) and angle (right symbol) you should stand on and look at the statue. There's a floor indicator hanging from the ceiling that shows you what floor you're on and the angels are marked on the elevator itself.
Find the correct angle on each floor and take a snapshot of the statue. Now go to the entrance level. The "flower" in the middle of the temple has six shapes on it that describe how the statue looks from different angles. Tap on the three that correspond to the angels you found.
Click here to see the correct symbols
Once you opened the flower, you can use the elevator to go up to the observatory or down but you still don't have all of the white crystals and you need them to continue. Go out of the temple and go right. There is an area with rock pillars and pedestals between them. You need to step on six of the pedestals in the correct order to open a door at the end. Use the six symbols you found in the temple in the order of the floors to find your way through the pillars. Note that the symbols are painted with light - they will appear as negatives of the symbols you found in the temple.
Click here to see the correct order
Once the door is open, go through it, up the elevator and into the lake area.

Lake Area
You go out to a cliff side with a huge blue carousel on it. Use the blue buttons on the floor to rotate it and get to the top of it. Take the white crystal and go down the ramp and elevator to ground level.
Here you will find a lake with some blue pillars in it and transparent white walkways between them. In the middle of the lake there's a small island with a closed black vault. You need to walk on the walkways in the correct path to open the vault.
Use this diagram from the gallery to find out the correct path. Each 4 vertical blue hexagons represent a blue pillar. From left to right you have seven couples of pillars in two rows. Each couple shows you the next two pillars you should go in between.
Click here to see the correct path
In the area next to the lake there are some stepping stones scattered on the ground with symbols on them. Step on them in the correct order to open the small garden you saw from the temple. Use this diagram from the gallery for the correct order. The first symbol is the lower one and the last is the upper, six stepping stones in total.
Now go back to the temple. Go into the central elevator. If you haven't already - go to the top observatory and get the white crystal. You should now have all of the five white crystals. Now go down to the lower level of the temple. The two hexagonal consoles control the rotation of the big stone cylinders. The consoles are connected - rotate one cylinder and the one below or above it will also rotate. You should create a path through the two cylinder floors to get to the lower level.
Click here to see the solution
Once you're on the lower level, insert the five white crystals to the lower part of the pedestal and a door will open...

Map room symbols:
Temple symbols:
Pillar path:
Lake path:
Cylinder maze path: