Archive of Unknown Universes: A Novel

From the critically acclaimed author of There Is a Rio Grande in Heaven, a piercing debut novel following two families in alternative timelines of the Salvadoran civil war—a stunning exploration of the mechanisms of fate, the gravity of the past, and the endurance of love.

""Beautiful."" —LA Times, A Must-Read Book for Summer

“An important voice in U.S. fiction. Ruben Reyes Jr. is a wonder.” — Héctor Tobar

Cambridge, 2018. Ana and Luis’s relationship is on the rocks, despite their many similarities, including their mothers who both fled El Salvador during the war. In her search for answers, and against her best judgement, Ana uses The Defractor, an experimental device that allows users to peek into alternate versions of their lives. What she sees leads her and Luis on a quest through Havana and San Salvador to uncover the family histories they are desperate to know, eager to learn if what might have been could fix what is.

Havana, 1978. The Salvadoran war is brewing, and Neto, a young revolutionary with a knack for forging government papers, meets Rafael at a meeting for the People's Revolutionary Army. The two form an intense and forbidden love, shedding their fake names and revealing themselves to each other inside the covert world of their activism. When their work separates them, they begin to exchange weekly letters, but soon, as the devastating war rages on, forces beyond their control threaten to pull them apart forever.

Ruben Reyes Jr.’s debut novel is an epic, genre-bending journey through inverted worlds—one where war ends with a peace treaty, and one where it ends with a decisive victory by the Salvadoran government. What unfolds is a stunning story of displacement and belonging, of loss and love. It’s both a daring imagining of what might have been and a powerful reckoning of our past.

© 2025 HarperAudio (Audiobook): 9780063336339

Release date

Audiobook: 1 July 2025