The giant popup seemed to just appear out of the sky and surprise these Brewers infielders

Sometimes it rains at baseball games. Other times, like in the second inning of the Brewers' 5-4 win over the Cubs on Thursday, it rains BASEBALLS:

Just kidding! It was actually a giant Addison Russell popup that fell for a single in between Orlando Arcia and Hernán Pérez. You can check out the full play in the main clip above.
Still, a book about baseballs raining from the sky might be decent.