I thought I wasn't going to get into the sewer for fishing. But, I went back in for the third or fourth time in a row and I was on the beam overhead instead of the parkour course. All I had to do was kill a few trolls (I admit I didn't really look at what they were) run along the pipes to the last section and wait to get to the boss. Once he was gone I was left to fish. He didn't come back, which I was glad for. I hope this will work again. I got the legendary, epic, all of the fish but I need more for the quest which turned up when I left the sewer.