How does this House Taken Over Story Create Suspense?

When the house is breached the first time and the intruders take over half the house on the other side of the mahogany door, there is no discussion of recourse between the narrator and Irene. They don't consider retaliation or calling authorities or anything like that. They simply consider that side of the house and everything in it totally lost to them. The ambiguity of the intruders and their identity leaves a vacuum of meaning in "House Taken Over." In other words, by not explicitly identifying the intruders one way or another, Cortázar leaves the story widely open to interpretation by the reader. The reader can map any number of forces onto the narrator and his sister losing their family home. It could be seen as a political force, a class uprising, or a foray into magical realism.

The takeover of the house certainly is not logical or realistic in itself, given that the bathroom is accessible from both sides of the house. The intruders do not seem to be aggressively trying to breach the other side of the house; it's just that one day, they simply are there. If these were aggressive conquerors, they would likely knock down doors and walls until they had control of the entire house. The slow progression of the takeover seems to suggest something less familiar to our world. On the other hand, the narrator and Irene seem to fear the takers-over as if they were some kind of violent force that could not be safely confronted or reasoned with. And when the narrator, upon finally vacating the house for good, locks the front door and throws the keys in the sewer, he suggests that he wouldn't wish an encounter with the new inhabitants on burglars. So, there is clearly an element of danger attached to the takers-over, but the danger remains undefined.