Not being one to enjoy getting squished by a rapidly-expanding boat, Eilina was a bit annoyed with the intrusion until she took a closer look. "That's a folding boat," she said excitedly. "Perfect for getting places that are blocked by water. I don't know about you all, but I'm not interested in going swimming, and there's only one place we haven't explored yet." 

Eilina pointed at the sewer river flowing under the bridge. "The water appears to be flowing North to South, if my bearings are correct. I suggest we look downstream first. If there is something going on upstream, I would expect to see evidence of it in the water."