The Shooting Star takes off. Soon, he's as high as his upper-story window, and a moment later higher still. Not much higher, and Number Twelve is hardly distinguishable from Eleven and Thirteen. Not that he's looking down.
"Regulus!" his father barks. "Come down here this instant!"
"But dad—"
"Now!" His knuckles turn red around the wand he is gripping.
Regulus unhurriedly descends.
"You know perfectly well that you only fly when we're away from Muggles. You could have been seen!"
Eyes on the ground, he walks toward the house.
"Give me the broom."
Regulus does nothing, so his father marches toward the door to intercept him. "Give me the broom."
Reluctantly, he hands it over.
"You'll get this back once you're mature enough for it." He opens the door and waits until Regulus has trooped inside before following him in and closing it.