Amy ran over to him. "Grandma?"
"Yes, dear?" Biff asked.
Dear? he thought.
"Watch me do a cartwheel," she said, excitedly.
Biff nodded, his knees starting to ache. "Be careful," he urged. All three kids seemed to have boundless energy. It was making him feel lethargic by comparison. He'd just sit here and watch, and catch his breath. He could figure out this mystery later.
