After a short cutscene, glide towards the statues.
In the centre of the square, there's a circle. Stand on it and read the inscriptions. After the text disappears, the camera will show you your next target - a book. Go there and read it.
This way you will start a fight, divided into three phases. There's a checkpoint after each of them, so you won't have to start everything all over again in case you die.
The first phase consists of killing mortal people and demonic hands appearing from the floor. If a mortal gets caught by the hand, he will turn into an undead, which to be honest doesn't make the fight much harder.
The second phase will definitely be more demanding. This time the undead will try to approach the bars - if they succeed in doing so before you kill them, they will turn into a stronger monster. One of them will turn into a Minotaur at the very beginning and if everything goes well, he should be the last one to do so. In order to quickly move around the area, ignore the big guy for now and use the right stick. This way no one will get pass you.
The Minotaur isn't an easy enemy, considering his speed, stamina and strength. He moves quickly and his attack takes quite a bit of health. His main and most dangerous attack is the charge. However before he uses it, he will take a characteristic pose, so you will have time to react. During his charge you can try to jump over him or counterattack with L1 + Circle (if you want to hurt him, you must act fast and be determined). The enemy will also use normal, close range attacks. There are two of them in a row, which can be quite dangerous.
In order to kill the Minotaur with the QTE, grab him and quickly press Circle. The finishing attack is quite easy to pull off, and as a reward you'll receive some health orbs (always, without exceptions).
During the third phase, you will have to face a Gorgon and Harpies at the same time. Focus on the Gorgon until the QTE symbol appears above her (don't kill her) and then take care of all the Harpies. This will result in another Minotaur showing up. Once he's there, kill the Gorgon using with the QTE and get rid of the horned monster, which should now be turned into stone. Afterwards there's another Minotaur and the fight's over.
After the victory, before you head to the statues, take a look left. You will find a destroyed bridge there. Jump to the other side and follow the ledge to the end to find some experience chests and a Gorgon Eye [!!!].
Now you can return to the statues and hear what they have to say by standing on the circle. You will have to go through a portal.
Once on top, head right and jump over the gap (there are blue crystals in the area, but you can't destroy them right now). A little further you will come across a tunnel [RS], where you will be attacked by two Minotaurs. On the higher difficulty settings you should make use of the exploding oil pots to your advantage.
Right behind the tunnel, turn right, where you will find another portal. Enter it and you will find a note on the ground, as well as a Minotaur Horn [!!!] (you will have to go through this portal in the later part of the game, but it's worth getting this upgrade right now).
Return through the same portal and continue moving forward, jumping over the gaps (on your way you'll pass by an experience chest). This way you will reach a spot at which you will talk with a mysterious girl (I won't tell you who she is). There's a rope nearby.
Grab it and cross to the other side (don't worry about getting attacked). Once there, jump down to the ground and go down the vine wall, into the cave. While crossing it you will find a note on the ground.
Right behind the corner you will get attacked by a new type of enemy. This time the undead soldiers will attack you with electricity. You can block them by pressing the button right before it hits you (holding the button all the time won't work).
Additionally you can grab them at all times and if they fall to the ground before dying, you'll be able to...
... finish them off effectively (without having to complete a QTE). If you don't grab them, they will explode after a while (that's why you should avoid them if they're crawling towards you).
A little further you will arrive at a room with a puzzle. Pick up the note from the ground and light the fire (with Apollo's Bow). Glide to the first ledge. Kill some enemies there and pull the lever [RS]. This way you will summon a lift. Before it leaves, jump onto it and reach the next floor.
There you will find an infinite number of movable pots. Move one to the place where the lift arrives and glide to the previous ledge. Afterwards once more pull the lever and together with the moving platform, get to the pot. Push it onto the platform and take it below. Now push it down to [RS], to increase the flame.
Now glide up, lower the grating and glide onto it. Thanks to it you will be able to open a door leading to a secret room. Inside you will find a big group of demonic hands (they pose virtually no threat), an experience chest and a Phoenix Feather [!!!].
Leave the room and glide once more, this time to the very top. There you will find and entrance, through which you'll get into a big room, with a nice view of the Tartarus included (on the right there's a chest with experience).
Before you head to the next location, you will have to fight the stone statues. They're very easy, considering the speed of their attacks (on generally the lack of any speed whatsoever). You will be able to dodge or block their hammer attack with no problem. Apart from that, the enemies lack any special moves - they can only slowly swing their hammers.
In order finish a statue with a QTE, you'll have to press two basic buttons at the right moment.
You'll have to jump into a hole in the floor to continue. Glide down and look out not to fall into the pit.