Continue your journey with Prima's Dark Souls 2 Guide and Walkthrough!
Reward: Royal Rat Vanguard Soul, Rat Tail
This boss battle is not just against the Royal Rat Vanguard. You must face off against a horde of rats, as well as the Royal Rat Vanguard. If the rodents attack too many times (even if you're guarding their attacks), they will petrify you. To avoid this, equip gear that increases petrification resistance, such as the Ash Knuckle Ring found in the Gutter. In addition, the Royal Rat Vanguard poisons you with each attack, so poison prevention gear and items should also be used if available.
Luckily, this is one of the easiest boss battles in the game. While normal rats continue to pile into the area, you only need to defend against them for a short time. Kill any rats within your immediate area as you move around the room to avoid getting ganged up on. After about a minute has passed, the health bar for the Royal Rat Vanguard appears.
Once the health bar is visible, look for the rat with a lot of fur on its back. It's the same size as all of the other rodents, so it may be difficult to spot at first, but it's the only rat with a lot of black fur on its back. As soon as you spot this rodent, lock on to it and don't change targets.
While this rat has more health than the others, you should be able to take it down by continuously attacking until your stamina bar is depleted. In the worst-case scenario, it should only take two stamina bars worth of attacks. If you need two bars, back away after depleting the first bar. If you move to the opposite side of the room, you'll have time to use a health item while the rats catch up. Heal, then go back in for the kill. Once the Vanguard is down, the remaining rats retreat. Kill them as they flee for additional souls.
With the Vanguard down, head through the doorway at the end of the room that was previously blocked by mist. Speak with the rat sitting on top of the pile of bones just ahead. He offers you the ability to join his covenant. If you join, you obtain the Crest of the Rat. Decide if you wish to join or not, then head through the corridor to the left.
Drop down into the room below (the same room you started in) and make sure you don't fall through the second hole and into the basement. Pick up the item to obtain a Pharros' Lockstone, then drop down through the next hole onto the coffins. Head to the coffins just below to the left, then make your way down to the bottom, using the coffins as a staircase.
When you drop down to the stone bridge (not all the way down to the broken wooden bridge), you will take fall damage, so make sure you're ready for the fall. Pick up the item at the far end of the bridge to obtain a Bleed Stone, then head to the opposite end of the bridge and look to the right to see an item below. Jump down to the tiny platform to the left of the item. Pick it up to obtain a Disc Chime.
Before you drop down to the ground floor, be careful. This is the room at the bottom of the well in Majula that leads into the Gutter. If you have not already been down there since the last time you rested at a bonfire, several enemies mount an ambush when you reach the ground floor.