"Guess he didn't like that little chum we left on for him," Bud said with a chuckle.
"Let's leave him where he is," Tom agreed.
The two boys went back to the adjoining apartment and were soon asleep again. Several hours later they were rudely awakened by a loud crash of glass and a heavy thud.
"Something's happening to Exman!" Tom cried.
With Bud at his heels, the young inventor dashed into the laboratory.
[CHAPTER XII]
EXMAN TAKES ORDERS
A strange sight greeted Tom's and Bud's eyes. In the first rays of sunlight, the space robot was moving back and forth about the laboratory in wild zigzag darts and lunges.
As he rolled toward a bench or other object, the brain energy seemed to send out invisible waves that knocked things over! Already the floor was strewn with toppled lab stools, books, and broken test tubes. The heavy thud had apparently been caused by a falling file cabinet.