It wasn't until after they had rescued their father that any of the Tracy brothers thought to ask:
"Hey Mechanic, what does the 'T' in the T-Drive engine stand for anyway?"
Alan was spending his last few days home before heading to college getting under various people's feet to ensure they didn't miss him too much; it was Brains and the Mechanic's turn today.
The Mechanic, elbows deep in his and Brain's latest project, rumbled back without looking, "Tesseract."
"What?"
The Mechanic paused, and looked over at the youngest Tracy skeptically.
"Have you never read A Wrinkle In Time?"
The tips of Alan's ears went red. He had heard John mention it, once or twice, or maybe a dozen times.
"No?"
"I'll lend you my copy," the Mechanic said thoughtfully after a moment, "I think you'll enjoy it," and then went back to quietly bitching out a stubborn hexagonal gear.