Continue your journey with Prima's Dark Souls 2 Guide and Walkthrough!
The enemies in this area are tough to stun, so attack once, then block or evade their next attacks. Repeat this strategy until they go down. Defeat the enemy dead ahead and continue toward the stairs to engage the next enemy. Take him down, then grab the 10 Prism Stones in the corner, but ignore the chest. If you access the chest, it comes alive and kills you! There are quite a few points where you can use a Pharros' Lockstone in this area. However, all of these points are traps and not beneficial unless fending off invaders in multiplayer.
Head through the small opening in the water to find a bonfire to the right. Light the bonfire, then head through the monster mouth doorway. Quickly kill the dog and the enemy just beyond before the invader appears. The larger enemy swings slowly, but will swing multiple times before pausing. Do not counterattack until you know it has stopped attacking. When both enemies are down, engage Bowman Guthry, the invader.
Guthry uses two crossbows, which means you don't have to worry about much at close range. He raises the crossbow he's about to fire, telegraphing this attack. He evades well, so keep this in mind as you attack. In addition, he uses an Estus Flask to replenish his life if you let him get too far away from you.
Take down Guthry to find a Royal Swordsman Armor. In the far right corner of the room (from the perspective of the entrance), pick up the item to obtain two Amber Herbs. Go through the doorway near the far left corner to reach the item on the balcony above. Pick up the item to obtain a Gyrm Axe and a Torch.
Head back down, then across the water and through the doorway in the other corner (far right from the original entrance). Take out the two rats that attack, then head up the ladder on the far side of the room. Pick up the item to the left to obtain a Twisted Barricade and the Soul of a Proud Knight.
Take out the enemy ahead and continue along the path to engage the second enemy. Just beyond the second enemy there are spikes along the right wall. The enemy in the alcove ahead activates the trap, but it only remains active a short time. Wait until the spikes retreat, then quickly run past the trap and take down the enemy in the alcove to the right.
The chest in the alcove is rigged with a poison trap that goes off when you open it. Be prepared to nullify the poison if necessary, then pick up the Titanite Chunk and Petrified Dragon Bone found within.
Continue down the path and around to the far side of the stairs just ahead. Pick up the item on the ground to obtain a Pharros' Lockstone and the Large Soul of a Nameless Soldier. Head up the stairs to reach the room you started in (only this time you're on the second level), then proceed to the left. Enter the first doorway on the left to find a bonfire and a mist door.
If you enter the mist door, you battle against the Royal Rat Authority. However, if you head back out first and continue down the path, engaging the enemies and crossing over two stone bridges, you'll find an item to the left after the second bridge. Pick up the item to obtain a Large Soul of a Brave Warrior.