Suppose that we live in a universe without “ifs.” What appears to be chance, or choice, is actually a peek into the rules of a completely separate universe that we can never access. Here, all our hopes for what might have been or what could be are accounted for; every outcome is settled, and we must play it as it lays.

Welcome to the vertigo-inducing contemporary cosmic landscape, which is also the landscape of Michael Zapata’s debut novel, “The Lost Book of Adana Moreau.” Structurally, the book alternates between the story of Maxwell Moreau, a budding theoretical physicist in 1920s-30s New Orleans, and that of Saul Drower, a hotel clerk and sci-fi enthusiast in Chicago in the early 2000s. The reader hopes these worlds will collide through an unfinished manuscript by Maxwell’s mother, the titular Adana.

The daughter of Dominican insurgents executed by the United States Marines in 1916, a teenage Adana flees the island with the help of a lovestruck pirate (Maxwell’s father), on a ship bound for Louisiana.

Settled with her new family in New Orleans, Adana discovers, like fortunate parents the world over, that literature is the best tether for her son’s wandering spirit. But it tethers her as well, and she attacks the library’s science fiction section with an autodidact’s frenzy. These titles inspire Adana to give voice to her trauma in the form of an apocalyptic novel of her own, a multiverse dramatization called “Lost City.” Tragically, typhoid strikes before she can finish the sequel, “A Model Earth,” and she destroys her only manuscript before she dies.