But Georgie had a secret weapon: his little brother. “Sheldon,” he whispered later, “if you help me get ungrounded, I’ll help you with your reactor.”

“No. Building a nuclear reactor.”

“A breeder reactor, to be precise,” Sheldon explained to his unimpressed mother, Mary, who was folding laundry. “If I build it in the garden shed, we could power the entire block for a decade.”

Mary sighed. “Sheldon, you are not building a nuclear reactor in the shed. Your father’s lawnmower is in there.”

“You’re grounded until you turn forty,” she snapped.

Missy smiled—a rare, genuine one.