You will learn that you have lost your mirror.
Additionally, you will have to wake up Trico.
Climb onto the beast, move towards his tail and start lowering yourself over it.
Along the tunnel, you will get to small balcony with a ladder.
Climb up the ladder to reach the lever above and move the grate up.
This way, it’s possible for you to jump into the neighboring corridor.
Jump down from the platform with the lever and go to the new area.
If this happens, start pressing all of the buttons to free yourself.
Do not have a go at fight the armors in any way, because you are defenseless right now.
The same applies to every encounter with this bang out of monsters.
Do not proceed on and go back, instead, to the location where you have left Trico.
The beast will wake up and attack the armors.
Climb onto him and keep tapping Circle to pet him.
After a while, Trico will calm down.
Once again, enter the corridor where you have encountered the armored knights.
Make it over to the neighboring corridor and call on Trico.
Turn back and take interest in the wooden beams shown in the above screenshot.
Jump to reach the first one and walk along over them.
This will take you to a chain that you have to grab onto and climb up.
Thanks to this, you will reach the ruins on the surface.
He should spot you and get here.

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