thud

THUD. That's the sound a plastic bat makes when it comes in contact with the back of a 34 month old girl's head, at the maximum velocity generated by a three year old boy. It causes severe panic on the part of the boy's mother. Internal organs migrate northward to the throat. There are tears, boo boo bunnies, and hugs. And an apology from the boy, after much coercion. 

Little girl recovers much faster than boy's mother. She has a lump on her head but is smiling before she gets back home. Boy's mother may never recover. She makes apologetic phone call to girl's parents, who both happen to be doctors. They laugh. This does not help mother recover. Nightmares will undoubtedly follow.