Early one morning the south-westerly wind arose from off the Atlantic, and brought fast low clouds over the land. A blown grey rain hid the trees on the slopes of the valley. At night the young moon was like a luminous grub spinning a cocoon around itself in the sky. The river pushed to the sea with the fresh, or brown flood-water, and at nightfall their holt, rising three feet under a waterside alder, was filled. The otters rode down on the fresh, over the spillway of the Dark weir, where branches were fixed amid long claws of water. They spread their legs and floated. The noise of the great waters filled Tarka with joy. A log rolled in front of him, and he scrambled on it, to jump off again with happy cries. He pretended that froth was fish, and turned over on his back, trying to clutch it. The river swilled him along, while he whistled in happiness. A memory of big fish was moved in the otter's mind by the smell of the fresh, and she was taking her cubs down to river-bend above Canal Bridge, where she and her mate had killed salmon and peal before the cubs were born. During the journey the clouds were blown to the north-east, over the high and cold moorland, and when the otters had drifted under Rothern Bridge the moon was shining bright in a dark blue sky. Bubbles glinted around Tarka's head, where the water, hurrying too fast over shoals, tumbled back upon itself. Round a bend the river began to slow and deepen--it was dammed half a mile below by a concrete weir built diagonally from bank to bank. This was the head of the weir-pool. The otters drifted on, round another bend until they came to where the smooth and thundering fall-over of the bubble-whitened water slanted across the river, broken near the left bank by the plunge of breakers down the fish-pass. A mist hung over the river. An icicle stood in the moonlight below the fish-pass, a silver spark for an eye. Below the fish-pass the water rushed in a foamy spate. Above, it slid black and polished. Presently out of the lower whiteness a silvery flicker shook and vanished. The silver spark vanished and glinted lower. Old Nog, peering below the pass, was so excited that he nearly fell over the three long green toes of each foot, in his haste to overlook more of the water. A second fish tried to leap the weir: with sideways flaps of tail it struggled up the spillway, but the claws of the water pulled it back. The moon in its first bright quarter was smitten into a myriad shimmerings by the lower turmoil. Suddenly, it seemed, the shimmerings were drawn together into a larger quartered moon, which rose out of the water in a silvery curve, and fell into the pool above, soundlessly in the immense roar of the fall.