Mystery Ranch: The Boxcar Children Mysteries, Book 4

Grandpa Alden's sister, Jane, is not feeling very well, and it's the Alden girls who go to care for her. Soon a mystery begins to unfold and the clues are everywhere; from the stranger on the train, to the beautiful yellow rocks on Aunt Jane's ranch. When Henry and Benny come out to join the girls, the four children find themselves unravelling the intriguing mystery.