Shrine of the Crusader

The Shrine is an Ayleid ruin, named Vanua, whose entrance is underwater. Those with poor Athletic skills will want to swim out over the entrance and then dive to it. Alternatively, packing some Water Breathing potions, spells or items will make getting in a simple matter.

Vanua is inhabited by undead, but is otherwise a fairly normal Ayleid ruin with a lot of twists, turns, tunnels through holes in the walls and that sort of thing. The path to the Helm of the Crusader is pretty linear, so it's hard to get lost on the way. When you enter a large room with a raised center section, a high, fenced-off area at one end, and the remains of Sir Amiel you're in the right place. There are a few ways you can go from here.

Everyone needs to get the ring from Sir Amiel's body because it will be needed for the next mission. Reading his journal is also necessary (it marks the Priory of the Nine on your overland map), but you shouldn't have to take it with you. Dungeon-delvers will need to take the key to open the gates and proceed into the next area, which will eventually return you to the fenced-in area. Players with high Acrobatics can just bypass that whole section by jumping over the fence, although it might take a few tries and running starts to get there. Having the Boots of Springheel Jak or some other Acrobatics-enhancing item/spell will make it a lot easier.

The Helm is laying out in the open on an altar and there are a few other goodies in the area. Help yourself. The Helm has several effects:

A note on the Relics. You can only equip them if your Infamy is either 1 or 0. If your Infamy ever rises to 2 or more, you'll need to repeat the Pilgrimage quest to drop it back to zero again. Thieves and Assassins take heed. And don't think that the Cowl of Nocturnal will get around it. "The gods will not be mocked." 'Nuff said.

You get out the same way you got in, so be prepared to swim.