In the meantime, the young inventor realized he had an awesome
responsibility. He must not only make the best use of the brain energy
during its stay on earth, but also keep it from falling into the hands
of treacherous Brungarian plotters.

Tom's thoughts were suddenly interrupted by the sound of girls' voices.
Sandy and Phyl were standing in the doorway of the space-communications
laboratory.

"Talk about deep thinkers!" Sandy said teasingly.

"Goodness, we had no idea we'd be interrupting a session of the brain
trust," Phyl added with a mischievous sparkle in her brown eyes. "Maybe
we should go away again, Sandy!"

"Hey! Hold it, you two!" Bud exclaimed. "What do you think, Tom--are
these the visitors we've been expecting from outer space?"

"Well! I like that!" Sandy pouted. "Do we look like a couple of little
green people?"

Tom chuckled and seized the opportunity to do a little teasing of his
own. "I think it's just your pointed heads that fooled us, Sis." Then,
as the two girls broke down in laughter, he added, "Why the unexpected
visit?"

Sandy and Phyl explained that they had come to invite the boys to a
picnic cruise on Lake Carlopa the next day.