The rat had skittered down the tunnels, turning at crossroads, with precision, knowing exactly where to go. Zoe followed it, solely focused on where the rat was. Cassius attempted to memorise the winding turns, wanting to be able to find his way back. They finally came up on a large empty cistern, the sound of rushing water drowned out their footsteps, they stood near the top of it. They both looked down as the rat climbed down one of the pillars lifting up the catwalk that crossed the cistern. They followed the rat with their eyes down to a 90 foot drop, to a lit bottom. Grated mouths in the wall allow the sewer water to run off before even rising to the raised platform in the middle of the cistern floor.