The chapter will start with a good look at Ares, the god of war. It looks like he's winning the fight against the opposing army, but there's nothing you can do for now. Ignore him and head down the left path (forget the right path for now - you'll get to that later). Smash the containers and then head through the opening.
A blast will cause the gate to close the door behind you, leaving you with no easy way out. Two minotaurs will spawn in front of another shut gate. Head to the back of the room (near where you entered) and you'll see an area of the floor that's circular and raised. Step on it to find that it's a large floor switch. Stepping on it will cause the gate behind the minotaurs to rise, opening up a new path for you. Unfortunately, it's not that easy. The switch is only active when a large-enough weight is placed onto it and stays on it. Have the weight move and the gate falls shut. What you'll have to do is lure one of the minotaurs onto the switch and then freeze it at the right time using Medusa's Gaze. Make sure you reach the gate quick enough, or the minotaur will break through the stone and the path will be closed. If you don't make it in a few tries and your magic runs out, the magic container by the gate you have to open will continually regain its magic orbs after use, so no matter how many times you try, you'll always have enough magic to get the job done. Get through the gate for a health container and a new path.
Head through the narrow path and you'll find yourself between many abandoned houses on the road. Jump back over the debris, then go back to the room you were trapped in previously to get magic orbs from the same chest. Once your magic power is full, continue through the streets, making sure to look through the houses for chests containing Gorgon Eyes, Phoenix Feathers, and experience orbs. Walk down the road enough and you'll come across some Medusas. Continue directing your attention to the Undead Archers first - their arrows don't do too much damage, but they can be annoying when trying to land an attack on Medusa. Eventually, you'll reach some barricades. Smash through them and move on.
The next obstacle you'll come across is a pair of ropes above a gap. Get across by swinging on the ropes (done by holding ). An opening to the left of the second rope holds an experience chest. Open it, get back on to the rope, and swing to land. All you have to do now is follow the path until you reach Athens Town Square.