THE HOUSES BESIDE the path faced away from the river. Back gardens, lying open to the eye, hinted at private lives. At that hour of the morning, curtains were shut and decks deserted, but the aura of revelation remained. Flowers yawned, bronze-leaved cannas, lilies striped cream and red. Nasturtiums swarmed over palings. A heavy-headed datura flaunted pale orange trumpets that darkened at the rim. In September a tall, spreading tree was hung with clustered pink. A man taking a photo of it with his phone said the tree was a Queensland hardwood. Frances would have liked to photograph it too, but she didn’t linger here, not even when passing the ramshackle house with a flight of stone steps that reminded her of holidays in provincial France.

      On this stretch of the path, hemmed in by fences and water, the difficulty was Rod. A hefty, muscled bruiser from the RSPCA, he was frightened of other dogs. Toy poodles were particularly unnerving. Coming upon a pair of them one morning, Rod tried to make a dash for the brown sludge under the mangroves. Surprised and heartened, the poodles seized the day. Telling Charlie about it, Frances said, “Wouldn’t you be frightened if tiny, angry people rushed at you shouting?” But at the time, with Rod wrenching Frances’s arm and the she-oak needles slippery underfoot, no one was amused. The poodles’ owner marched them on, saying, “Come along, boys, not everyone’s friendly.” Rod hung his head, screwed his paws into the ground, and wouldn’t budge. In the end, Frances had to pick him up and stagger past the malevolent spot recently occupied by poodle. Frances did Body Pump at the gym, but Rod weighed sixty-six pounds. In the shower, she saw red welts across her stomach where he had clawed her in fear.

      The poodles had never returned. But sometimes there would be a dog in a garden—like the white bull terrier alert behind a fence. Rod’s tail drooped, and his ears. Picking up her pace, Frances saw a woman in the shadowy depths of the garden. She wore a wide hat and a trailing pink dress; a white hand emerged from her sleeve. There came upon Frances a sensation that sometimes overtook her when she was looking at a painting: space was foreshortened, time stilled.

      For the rest of that week, Frances kept an eye out for the bull terrier. A white stripe: danger, the surf that marks a hidden reef. But where had she seen him? Not at the French house, not at the one with the spreading tree. Had there been oleanders near the fence or a clump of banana palms? She remembered dense plantings, green gloom. The fence wasn’t solid—Frances and the bull terrier had inspected each other through it—but plenty of gardens ended in railings or mesh.

      Frances had pretty much forgotten the bull terrier when she saw him again. He was sniffing around a tree, but lifted his head as she passed. A few days later, Rod began to whimper—the bull terrier was at his fence. Some distance behind him, the woman in the old-fashioned dress stood beside a flowering shrub. She was a sidelong glimpse through sunglasses and a coarse veil of latticework, there and gone again at once.

      These partial visions, half-encounters, were repeated at intervals over weeks. One day, striding past the woman and her dog, Frances realized that whenever she saw those two she was the only person on the path. The morning swayed, as duplicitous as déjà vu. When a cyclist appeared around a bend, Frances considered hailing him—but what would she say? “Can you see a woman in that garden?” She heard him answer, “There’s no one there.”

      FRANCES AND CHARLIE had left Melbourne so that Frances could take up a research fellowship at a university in Sydney. She was