"And Nobby wasn't even the worst. Ankh-Morpork had a river so polluted you could walk on the crust on top mostly safely." And she knew of at least one dog who'd been loaded in a sack with rocks, tossed 'in' the Ankh, and squirmed out of the sack to trot back to allegedly solid land no worse for wear.

She wondered absently how Gaspode was doing. Likely well, as he was quite clever for a dog. "So never you mind the musty bird smell. At worst, I can smell you coming, but I could do that anyway."