Margaret Caldwell had moved her heavy velvet armchair right next to Henry at the end of the table.

She touched her pearl necklace with one hand while Henry spread his hand-drawn aviation diagram flat across his white cloth napkin.

“The main rotor blades create lift, but they also create torque that tries to spin the fuselage the opposite way,” Henry explained, standing with his feet shoulder-width apart like a guard.

“So the tail rotor gives counter-thrust to keep the helicopter steady during search-and-rescue missions,” Henry added, pointing his index finger at the detailed rotor assembly drawing.

Margaret wiped away a tear with the corner of her linen napkin, her stiff matriarchal posture softening into genuine affection.