"Ami machh-bhat khabo," she yells. The voice and taste of another girl, a past life from the Sundarban, has returned in Varsha's mouth. So have her memories, of being bitten by a snake, and a different mother.

As we move from Calcutta to Virginia, New York to Kolkata, more like her emerge. Dubbed "cases of the reincarnation type" by psychologist Shoma, these otherworldly beings from different cultures see visions of a broken future and a violent past engendered by the climate crisis. In 'Ghost-eye', the uncanny spirits of the Sundarban travel far and wide, taking fashionably new shapes that fit a more capacious, more current universe of ecological grief, but lack the elusive pull and convincing uncertainty of 'The Hungry Tide'.

The most deliciously written episodes are encounters with food, whether in the kitchen or deeper waters. Grounded in everyday cuisine made from seasonal, river-borne Rui and Catla, Shoma's eating game with Varsha is enthralling in its narration. Varsha's elaborate antics with boti come a close second. She reminds us of what Shoma and others in the region have lost in the wake of progress and ruthless capital - an intimacy with fish, a sense cultivated in the body over years of hunting and cooking by the river. This is an ability otherwise invisible and unlauded, marked by caste, class, and region. Rendered in sharp, delectable detail and unassuming complexity, the world of meanings and movements surrounding the mangroves comes to life again, revealing Ghosh's mastery over questions of ecology, migration, empire, violence, and the (non)human condition.

This is ambitiously placed in a larger universe. There is an otherworld of spectres with varying powers, peopled by "cases of the reincarnation type"; this dimension lacks lustre and detail. The narrative voice is divided too. While researcher Dinu narrates more than half of the book, there are chapters written in an omniscient voice, which mentions the Vietnam War, the moon landing, and Indian riots in the same breath. It brings up fascinating contexts, but instrumentalises them quickly in service of a larger picture, turning them into evidence of the existence of an otherworld.

While crises across the globe are connected to each other, these lines are overdrawn, and symbols are made so apparent that the larger picture loses depth. For instance, there is neither strain nor comfort in Tipu's relation with Dinu, and no shadow of old trauma in Tipu's manner, even though he is a climate refugee and a restless activist. He merely drives the plot in dry conversations with Dinu, where he directs him on what to do next. He never leaves a register of speech that seems to be taken from decade-old Internet memes, betraying any sign of seriousness. "Spill the tea" is spoken repeatedly, a Gen Z edifice without a character behind it.

The ghost doesn't linger tragically, or mysteriously; it comes with an explanation. Shoma's dream, for example, could have given scary cadence to the plot, but Varsha's supernatural presence in it is explained twice, once by Shoma and then by Dev's supernatural vision. Or the episode of the great snakehead, a fish turned angry and murderous after being trafficked away from the Sundarban. Its eerie gaze towards Dinu is marred by the grand explanation of Dinu's past life as an otter. Even footmarks in the mud have a reasonable ending. Jung is quoted in the novel as an explanation for these, "There are no coincidences, only 'synchronicity'."

Without an encounter with the unknown, the uncanny loses its fang. It no longer marks the limits of our imagination. It is reducible enough for Tipu to upscale the 'Sundarban experiment' as a solution. In moments like this, the novel forgets the unscalable, large planetary realm. The cobra is no avenger.

Rich in myth and lore, one might imagine that the power of 'Ghost-eye' lies in the miraculous incarnation of Manasa Devi, snake goddess and protector of the forest. She appears in the midst of tigers, activists, devotees, police, cameras and dolphins, marking an undeniable divinity of nature, and an imperative to stop bulldozing the mangroves. But Ghosh is at his most distinct when he speaks of fish. Life, food, neighbour, and allegory at the same time, fish is also an ordinary being. It is the spirit of a people surrounded by water, of a forest that doesn't need the presence of otherworlds to be uncanny.

The macabre outline of a hanging root excites more in Ghosh's pen. And the Calcutta of Dinu's childhood, engulfed in the inky darkness of a power cut. Sounds come floating in from great distances - trucks backfiring, jackals howling, someone blowing their nose - a distinct world of unfamiliars.

Ghosh's next has already been promised to posterity at Oslo's Future Library Project. We hope he returns with meatier ghosts.

- The reviewer teaches at Ashoka University