Aunt Eloise invites Nancy to New York City to meet her detective friend for a mystery case in Illinois. Detective Boyce tells the story of a wounded French missionary in 1680. The French missionary was nursed and regained consciousness only long enough to say 'Valuable message in hollow oak.' Then he died. Detective Boyce and his friends found a hollow oak, but there was nothing inside the trunk. Before they could locate another hollow oak with an arrow, they have to fly home. Detective Boyce hopes that Nancy will go to that area and undertake the search to finish the case for them. However, she needs to be careful with a man called Kit Kadle. He is eager to find the message by himself and disallow others to discover the hidden message before him.
Detective Boyce suggests to her to room with the girls from the Archaeological Department of Paulson University that are staying in a rented farmhouse with Miss Bancroft. Unfortunately, Miss Bancroft is difficult to be reached since she has no telephone and seldom go to town to pick up mail. After telling Ned that her father disapproves her to travel alone, he tries to contact his cousin Julie Anne from that university to help Nancy to get a room at the farmhouse.
When she is on the plane to Illinois, a stranger is interested in her trip and asking her a lot of questions. Later, she learns from another passenger that the stranger is Kit Kadle, who is a conman. Then, when Nancy is at one of the hollow oaks with Julie Anne and Clem, a helicopter is circling above and spying on them. On the next day, when the pilot introduces his passenger, Mr Wilson, to Nancy, she suspects he is Kit Kadle in disguise. When they report a trespasser incident to the state trooper, they find out from an elder Indian that the hidden message is about the missionary's treasure.
This story is quite dull for me and probably the most boring I have ever read from this series. The part that I disliked the most is about Art's interest in Nancy and his jealousy on Ned. Worrying of Art's upset with Ned's arrival, Nancy invites him to come to the towboat trip as well. Nancy's friends try to help to ease the tension, and Nancy's attention is being highlighted throughout the story. Isn't every mystery case has shown enough the importance of Nancy, why we need such love interest to increase Nancy's attention?
I'm glad that I was able to skip several chapters and fast forward to the last two chapters. It seems I didn't miss any important details and I got to know what happened to Bob and the hollow oak with the treasure. I think besides Art's interest in Nancy, the towboat trip has killed my interest in the story.
Rating: ★★★ (1/5)
More reviews can be found on Goodreads: The Message in the Hollow Oak
(Nancy Drew Mystery Stories #12) by Carolyn Keene.