Ye gods!
He recoils as much from the rancid stench as the torrential mass of gushing filthy liquid. It's an outhouse! — is the first thought in his head, but outhouses weren't so large nor did they have walkways and gigantic, monstrous rats! He fights to keep his balance — an act aided by his squat frame and low centre of gravity — as falling into the muck and getting that foulness into his beard and nose is the last thing he wants to do. With how the flow of water fails to cease, he can only think that it must be the work of whatever strange magic lies on this house.
The badly-drawn symbol on the door, right in front of his face — the sudden jolt to his head from this olfactory assault is enlightening. He thinks, if he squints, that it resembles a woman, and remembers the strange shock that he'd felt when he turned the handle. Perhaps the door is cursed, he wonders, against the touch of menfolk.
He's about to draw a wand and drive back the rat with magical missiles, but the elf beats him to it. Instead, Bierstout grabs the door again and attempts to close it against the flow. "Help me shut the door!" he bellows, hoping that Varrys and Boris can hear him over the din of the rushing water.