Mystery Ranch — Gertrude Chandler Warner

One warm night four children stood in front of a bakery. No one knew them. No one knew where they had come from.

Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather and are spending the summer out west on their Aunt Jane's ranch.

Aunt Jane, their grandfather's sister, is a very unhappy woman who hasn't spoken to her brother in years. The Boxcar Children try to help her, but it isn't until the end of the summer that they learn Aunt Jane's secret -- and make a surprising discovery about Mystery Ranch.