Remarkably, Nathan's hearing improved dramatically with his change into mouse form. His tiny ears picked up every sound in the house, down to the ticking of clocks in distant rooms and the humming of appliances and electronics. He didn't just hear with his ears, either. His body seemed tuned to pick up on even slight vibrations, such as the one caused by the opening and closing of the front door to the house, as well as the subsequent footsteps on the floors of the house.
It was certainly also an unexpected development since he had expected to have the entire house to himself for the next couple of hours. Of course, he was curious, wondering who had interrupted the time he had set aside for exploring life as a mouse. He could leave his bedroom and seek out the source of the footsteps that continued to make themselves heard and felt by the tiny, white mouse. Or, and he timidly didn't have much disagreement with the alternative, he could simply stay put, hope whoever it was would just go away, and wait for the two hours to count down and let the device reverse his transformation.
After some debate, curiosity won out and Nathan scampered beneath the door of his bedroom with surprising ease. He felt a little nervous in the vast, relatively empty hallway. All the noise was coming from downstairs on the ground floor of the house. His nose wrinkled and his whiskers twitched as he sought out any tell-tale scents that might offer him some clues.
It was the painful sound of the engine of a vacuum cleaner that finally brought a jolt of realization into Nathan's brain. His parents employed a part-time housekeeper to clean three days a week and he had picked one of those days to run his experiment with the Chronivac.
It was a minor setback. He could just run back to his room and hide out there until she left. The plan might have worked, too, except at that moment a pre-teen boy appeared at the top of the stairs and peered down the hallway. Nathan squeaked in surprise, not expecting to encounter anyone while he was in his mouse form.