From the back of the book:
Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather, and they are playing in a community basketball league.
The Aldens are thrilled that Buzz and Tipper Nettleton, Greenfield's most famous basketball stars, are coaching their teams. But some of the other coaches don't seem
so happy to see the Nettletons. Then Tipper's Most Valuable Player trophy is missing, and Buzz's practice schedules get mixed up. Is somebody trying to foul up
the community league? It looks like it's time for the Aldens to solve another mystery'