The Magic Tree House series by Mary Pope Osborne continues to be a hit with younger readers. 
“Danger in the Darkest Hour” is the newest title in this collection and is the first in the Magic Tree House Super Edition series. Random House states that the reading level remains the same as books 29-52, but this new series has longer and more complex plots.
In this new adventure, Jack and Annie travel through time to June 4, 1944, days before the Allied invasion of Normandy. Teddy and Kathleen, the young enchanters, have been sent by Merlin to London to bolster morale. Teddy and Kathleen have become secret agents in the SOE, Special Operations Executive.
On a mission to France, Kathleen has disappeared, and Teddy needs Jack and Annie’s help to rescue her. They must parachute into Normandy to find her.
The book contains maps and an overview of World War II. Definitely more sophisticated than other books in the series, the new Magic Tree House Super Editions series may attractive another group of young readers