It's near the end of the Spanish Civil War and ten-year-old Carlos (FERNANDO TIELVE) has been left at the Santa Lucia School that houses orphans of the conflict. Told the ground rules by the steely and one-legged headmistress, Carmen (MARISA PAREDES), Carlos tries to cope with this unexpected turn of events.
He quickly surmises that among the other boys there, Jaime (IÑIGO GARCÉS) is the leader who quickly wants to prove the pecking order of the place. Among the adults, there are the instructors -- Victor Cásares (FEDERICO LUPPI), an older professor, and Alma (BERTA OJEA), a teacher - and the staff including Conchita (IRENE VISEDO), the cook, and Jacinto (EDUARDO NORIEGA), her angry fiancé who grew up there and now serves as the caretaker.
Then there's Santi (JUNIO VALVERDE), the ghost of another boy who haunts the place and warns the others to leave before imminent doom strikes them. With a huge, unexploded bomb stuck in the courtyard grounds serving as a symbol of the situation's explosiveness, Carlos simultaneously tries to avoid the ghost but also learn the truth about Santi's death. When the greedy Jacinto sets into motion his plan to finally break free of the place, it's only a matter of time before all hell breaks loose.