Each of the pipes has a different rhyme, once you know which of the items goes in what pipe place them in the following order.
Hand (from the grill, first left after entering from Copper Coronet)
Ring (2 skeletons on the wall near the entrance)
Blood (Carrion crawler, the worm next to the weird old man. Watch out for traps.)
Staff (A small group of Kolbolds will have them, they are at the far right side of the stream in the middle sewer which has the door/bridge.)
You will get a nice +3 sword and some exp, though I will warn you now that your reward is a mixed blessing (technically known as the Anomen affect).
