Published the year L. Frank Baum died in 1919, ‘Mary Louise Adopts a Soldier’ is the fifth book in the children’s series and is widely considered to have been completed by an anonymous author, based on notes Baum had previously written. Set in post-WWI America, kind-hearted Mary Louise decides she would like to help a returning soldier who mightn’t have any family or friends to welcome him home. She persuades grandpa Jim to take in Danny Dexter to work as their chauffeur and gardener, but one day Danny mysteriously disappears and Mary Louise must work quickly alongside her friend and trainee detective Josie O’Gorman to track Danny down.