With Highcastle, Stanisław Lem offers a memoir of his childhood and youth in prewar Lvov. Reflective, artful, witty, playful—“I was a monster,” he observes ruefully—this lively and charming book describes a youth spent reading voraciously (he was especially interested in medical texts and French novels), smashing toys, eating pastries, and being terrorized by insects. Often lonely, the young Lem believed that he could communicate with household objects—perhaps anticipating the sentient machines in the adult Lem's novels. Lem reveals his younger self to be a dreamer, driven by an unbridled imagination and boundless curiosity.

In the course of his reminiscing, Lem also ponders the nature of memory, innocence, and the imagination. Highcastle (the title refers to a nearby ruin) offers the portrait of a writer in his formative years.