Amycus's cries as he fell from the sky were enough to clear Rookwood's mind, and to focus on the immediate situation. He had no idea where he was, or why he was on a broomstick, but he did know that if he didn't help Amycus that he'd be dead very soon. He pulled the broom into a steep dive and an intercepting course. But Amycus didn't realize that help was on the way and decided to risk an emergency apparition just as Rookwood reached out from his broom and grabbed his shoulder.
There was a loud crack and most of Amycus Carrow disappeared, along with Rookwood's left hand. The former Unspeakable howled in pain and at the stupidity of his underling, whose splinched right buttock was still free-falling towards the ground.
Rookwood pulled out of his dive, struggling to maintain control of the broom with one hand, and quickly considered where Amycus might have gone off too. Expecting the worst and hoping for the least worst, Rookwood concentrated on a destination and disapparated.
He reappeared in the still-smelly living room of the Bristol safe house.
"Amycus?" he bellowed.
While there was no verbal reply, the sound of moaning from upstairs suggested that he had guessed right. He ran up the stairs, pushed open a bedroom door and threw a whimpering Death Eater off of a bed.
"Where's my bloody hand, you fool?" he demanded.
Amycus sobbed loudly as he pointed towards the bed.
Rookwood scowled as he spotted his splinched appendage within the soiled sheets. He grabbed it with his good hand and carried it over to a chest of drawers that was merely dusty. After placing it on the top of the chest and positioning his stump, he drew his wand and began to swish its tip over the breach. After a complex incantation and a bit of time, his hand was unsplinched.
The former Unspeakable strode back to the bed and yelled, "Get up you whimpering fool, we need to go now."
"But why?" Amycus asked. "This is the safe house."
"It's no longer a safe house now that you've splinched yourself trying to apparate here."
"But my bum!"
"You left it behind for the muggless to munch on, and there's no going back."
"But my sister!"
"Dunno where's she's gone to."
Carrow paused, then lamented once more, "But my bum!"
"Oh, quit whining," said Rookwood, as he turned a muggle alarm clock into a portkey. He grabbed Amycus's hand and placed it on the clock, adding, "Maybe if you ask nicely the Dark Lord will fashion you a new bum made of silver."