The idea of a missing author is very intriguing. The drawings are incredible and beg you to provide the story. I have, in fact, had my children write short stories from them as school exercises.

Van Allsburg, like David Wiesner, is an artist who uses the illustrations to tell most of the story. His work is less whimsical. The Mysteries of Harris Burdick is my favorite of all the Van Allsburg books. Each picture has its own mysterious story to tell.
RL=K-3rd     *Any level could use as a story starter for creative writing.