Margaret Sutton wrote 38 volumes of the Judy Bolton Mystery Series between 1932 and 1967. During this period, Judy amassed quite a following and her adventures entertained a generation of young adults.
Based on real life events this volume, her 29th in the series, features Blackberry, Judy's black cat, who finds a curious little pink china wing in the garden.
The Judy Bolton series is unique in that the characters age and address significant social issues along the way. As our protagonist, Judy has a strong character, is smart and a bit of a feminist.
Interestingly enough, the last twelve books in the Bolton picture cover series, this being one, had limited printings and thus are rare, more valuable and are highly collectible.