When they finished their search of the living room, the man suggested, "Let's search different rooms. You take a bedroom. I'll take the dining room. No telling where the safe is. They put it in a different place in every house."
The house waited, its electronic brain whirling.
It made a decision.
Silently, the house erected an invisible energy screen around the dining room. The screens were designed to block collective sounds of the entire house from any room and provide it with a comforting serenity.
Now, the house thought, the sound-screens will be most useful!
The house watched as the man in the wrinkled brown tunic examined a table.
Silently, panels in the walls opened.
A dozen machines a foot in diameter converged at a position behind the man's back.
The machines moved simultaneously, silently. They attached themselves to the intruder's body. They dusted and scrubbed him thoroughly, as if he were a piece of furniture or a floor.
The man screamed and fired wildly with the gun. The small machines crumpled one by one.