Once Upon a Time (Bomb) is a charming memoir of a young boy growing up in El Salvador. It tells the story of Alfonso Duque the Thirteenth, a youngster from a poverty-stricken family and a budding poet. Surrounded by hovering women-his mother, aunts, grandmothers, and sisters-little Alfonso still manages to enjoy boyish pranks and endure scraped elbows, knees, and ego while also discovering the pleasures of reading. The womenfolk laughingly describe him on his "throne" atop the trees or back in the outhouse, where he often escapes to read. This work of innocence is set against a darker backdrop of the growing violence in the Salvadoran countryside and the news coming from the fronts of the Second World War.

Argueta incorporates many of the best-loved local folktales into the narrative, the Siguanaba, Chinchintora the Snake, Theodora the Coyote, some of them personalized or hilariously adapted by the women to fit their own circumstances.

In the book, the author works through memory, re-encounters a nostalgic past, re-creates paradise, and re-acquaints himself with his poetic roots after years of exile from poetry, his homeland, and the luxury of dreaming.