"Stop him!" Bud yelped.
Exman was heading straight for a plate-glass window! Reaching from floor to ceiling, the glass formed one entire wall of the laboratory.
"Oh, no!" Tom tensed, realizing that it was hopeless to try to stop Exman in time.
But an instant later, the rolling robot stopped of its own accord, as if registering the fact that its energy waves were now striking a fragile surface. The thick pane of glass vibrated in its frame.
"Good grief!" Tom wiped his brow. "Let's corral that thing before he wrecks the whole lab!"
Exman was already rolling off on a new tack. The two boys managed to grab him before more harm was done. The brain energy in its container seemed to calm under their touch.
"What in the name of space science triggered it off?" Bud wondered out loud.
"Time. It must have reacted to the passage of time," Tom conjectured. "I suppose it just decided to explore this place." He added a bit nervously, "The sooner we can communicate with this energy, the better!"
"But how?" Bud asked.
Tom's brow furrowed. "Say, I wonder if Exman might understand a direct order?"