Dorothy Dale to The Rescue (Illustrated)

is the 13th and last in the series: Both Dorothy and Tavia are engaged, but no dates have been set for the marriages. Garry Knapp, Dorothy's finacé, is running a ranch in the west he inherited. But some good-guys-wanna-be-bad guys kidnap Dorothy's youngest brother in hopes of getting him to plead to Garry to swap his ranch for his release. Sadly for them, they didn't reckon on having to deal with Dorothy and Tavia!