In The Winter Dark is a 1988 novel by award-winning author Tim Winton.
Night falls. In a lonely valley called the Sink, four people prepare for a quiet evening. Then in his orchard, Murray Jaccob sees a moving shadow. Across the swamp, his neighbour Ronnie watches her lover leave and feels her baby roll inside her. And on the verandah of the Stubbses' house, a small dog is torn screaming from its leash by something unseen. Nothing will be the same again.
(from the dust jacket)
A very short novel, the 1988 hardback edition is approximately Penguin paperback sized and runs to 132 well-spaced pages.