Can Anyone Help Me With A Quest

There is this quest about a prisoner in ragni, and I need to get the key by finding the person who has the key in the sewer, does anyone know where is the sewer?

 

Go to the exit of ragni, jump down a bridge, swim up some water coming out of a pipe, trust me you cant miss the pipe, plus ragni has 3 exits so jump down the exit with the first Quest NPC

 

So I just find a pipe in the waterfall thing?

 

No look for a pipe with a water fall coming out

 

I found it but i dont see the villager in the pipe, just lv2 rats

 

Hm go left if hes not there go right and look for a room made of coal blocks

 

i found the villager, thx

 

No problemo And to get out jump out the pipe and swim left to find some stairs