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 secrets 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.