Answer:
That it was terrifying enough to make them forget their valued possessions.
Step-by-step explanation:
The given excerpt is from the short story House Taken Over (Casa Tomada) written by Julio Cortázar. It tells about a brother and sister living in a home taken over by unknown entities. The story belongs to the genre called magical realism, which was common among mid-20th-century Argentinian writers. The story starts realistically, but then natural laws slowly become distorted.
The excerpt is located at the end of the story, when the protagonists leave the house, and tells us that the entity was terrifying enough to make them forget their most valued possessions.