OK, now go to the door at the other end of the room and pull the lever to open it. Watch out for the Possessed Armor enemy with a flaming sword and bow just after the next set of stairs - it wakes up as you near the stairway and lets rip. Don't use ranged until it has taken full form or you won't hit it and watch out for its flame sword attacks if it rushes you. Oh, and when it seems as though it's down, it's probably just preparing its spinning sword attack. Remain vigilant. Once it's dead, go down the stairs and pocket five Large Titanite Shards, Human Effigy, two Twinkling Titanite and Dried Root. (That's a pretty solid Saturday night in right there.)
Next, there's a Fume Sorcerer round the corner, attacking from a nearby cliff. And if you try to get close, a bunch of Axe Demons will come at you from every direction. Stick with ranged attacks to deal with Fumey, although if it falls off the cliff don't assume you're safe - it can still hit you from below. Once he's down, there's another one waiting to peck away at you from further ahead. Again, go ranged. There are pillars here to help dodge its attacks. There's also a Human Effigy to the left.
Next up, there's another ladder and there's an invader lurking below. But that's not all! Part way down the ladder, more enemies emerge to one side. As soon as they do, go back up and use ranged attacks on them. Otherwise the invader is a right pickle. He's still tricky on his own, but you should be able to handle him if you've come this far - just kite him up the ladder for a few free hits as he ascends and then finish him off.
At the bottom of the ladder, you should see remains part-covered in snow on your left. There are some soul items in amongst them (including Soul of a Proud Knight), but be careful as you go, because two enemies will jump out of the soot and quickly attack. They're both close to the left-hand wall.
There are two ways forward now: down the stairs and through the door on the left, or straight forward and through the door on the right. If you want to go left, follow path 1A and you'll end up with an Alonne Greatbow +5, a Majestic Greatsword and two Bonfire Ascetic. Alternatively, jump down to section 1B of this guide if you want to go right and continue to the boss. (If you need a bonfire urgently, go with 1B.)
First up, there's a Raw Stone at the end of the balcony on the left. Grab it, then move over the big chain to the area ahead. Maldron the Assassin will invade and lurk nearby on the left, while there's a big stairway on the right that goes to the bottom of the tower.
There is a chest with two Bonfire Ascetic in it up top, but Maldron is between you and it. Once engaged, he bolts down the stairs. Maldron likes to hit you multiple times quickly, then pause briefly and land one more hit. With judicious blocking it should be quite easy to navigate behind him for a critical hit.
However, before you do that you will need to pass through an area filled with curse as you descend the stairs. There are several enemies also. There are two alcoves to the right of the stairs, the second of which contains an Ashen Idol, and destroying this removes the curse. It's a good idea to ignore the chest and invader and go straight for this idol. Then go back up the stairs quickly to avoid being jumped by multiple enemies at once. (Make haste, because otherwise you can get trapped in the alcove with the idol.) There are two Axe Demons on round platforms nearby, along with a Possessed Armor part way down the stairs (which cannot be killed until the Ashen Idol is ended).
Assuming you can prioritise and cope with all these threats neatly, you'll be rewarded with five Silver Talisman (to the right), the Alonne Greatbow +5 I mentioned (second round platform) and a Majestic Greatword in the chest at the bottom, although watch out, because there are yet more Axe Demons guarding it - three of the beasts.
Back in the room with the two paths, take the right fork instead, head through the fog door and go down the stairs. There's a Spell Quartz Ring +3 (magic defence) on the other side of the area and a bonfire in the next room. There's also a minotaur head near the centre of the main area, but you will need a Scorching Iron Scepter to activate it.
Left of the bonfire there should be two Magic Stones in the next room. Go along the next passageway and down the next ladder. Be prepared to do some ranged fighting. At the flaming statue you encounter, there are a few enemies on the right, including two of the explosive barrel carriers and a Fume Sorcerer. Shoot the barrel-carriers to blow them up, or hit the minotaur head to send it down the passage, taking them out in the process.
There's a lever here, but ignore it for now and go down the next passage. There's another flaming statue, as well as another Fume Sorcerer to its left, although Fumey won't emerge until you get there, so close in and be prepared to back up quickly. Strike the flaming statue and it will be pushed along the passage towards more lurking Fume Sorcerers. Move to where the first one showed up and you should be able to tackle these guys at range.
Yank the next lever, then use ranged attacks to handle the enemies with explosive barrels in the room ahead. There are a few here, so be careful to make sure you get them all and stay out of the room itself to avoid possible explosions. When you're sure the coast is clear, head on in and make sure the guy on the stairs on the right is also toast.
After rings and other loot items? The first page of our walkthrough points to Crown of the Old Iron King rings, weapons and items.