Lois Duncan books in order
19 books in the catalogue, about 68 hours of reading in all; the shortest takes 35 minutes and the longest 6 hours.
19 standalone books in the catalogue.
Standalone books
Five Were Missing 3.2 h 
They Never Came Home 3.5 h 
A Gift of Magic 3.7 h 
I Know What You Did Last Summer 3.7 h 
When the Bough Breaks 3.3 h 
Down a Dark Hall 3.3 h 
Summer of Fear 4.0 h 
Killing Mr. Griffin 4.5 h 
Daughters of Eve 4.9 h 
Stranger with My Face 4.6 h 
The Third Eye 4.0 h 
Locked in Time 3.8 h 
The Twisted Window 3.4 h 
Don't Look Behind You 3.3 h 
Ransom 3.2 h 
Who Killed My Daughter? 5.9 h 
The Magic of Spider Woman 35 min 
Gallows Hill 4.2 h 
I Walk at Night 35 min