Wren notices the sounds getting quieter, which suggests that whatever it is, it's moving away from them. It's hard to nail down distance with the echoing noise off of the sewer walls, though, but whatever is creating the noises is beyond the range of anyone's darkvision at the moment.<br/><br/>Ghaazala notices that the rats, which range from several inches long to nearly a foot in length not counting the tail (which everybody knows is just how big these rats can get, nothing special there), seem to have been killed in peculiar ways. Some of the whole rats appear to have been stomped to death, others seem to have been squeezed to death. Concerning the rat halves, some of them have been torn in half based on the fraying of the flesh and the fact that none is missing, while others have been bitten in half with several bites. Ghaazala isn't able to tell what bit these rats in half, but it looks as though each chunk that was bitten off was no larger than a handful of flesh.<br/><br/>Serge is able to learn all of that, too, but when he looks at the shapes of the bites he doesn't think of "what" did that, but of "who". The bites look as though they came from a human mouth. As for what could be in the water, Serge knows that a lot of things live in the sewers, including vermin, oozes, bats and rats, but none of those would really have produced sounds that Wren would have considered as sounds of something moving through the water. Even a big rat wouldn't make enough of a noise to hear over the flow of water, most likely.<br/><br/>Concerning what could be in the water, Ghaazala knows that virtually anything that could have swum up from Waterdeep Harbor into which the sewers empty at water level (so there's no small waterfall of sewage coming out of a pipe into the harbor; a fish could swim into the sewer without having to jump like a salmon swimming upstream). However, some of the things that she knows could be here specifically are all types of vermin, oozes, stirges, bats and rats, fish of all types, and even the occasional crocodile or other large creature.<br/><br/>Ghaazala can't hear anything over the echoing flow of water through the pipes.