Classic Kids Mystery

While riding in their homemade iceboat on the frozen surface of Barmet Bay, Frank and Joe Hardy and Chet Morton discuss their plans for the upcoming Christmas holiday break. They visit Cabin Island but a mysterious stranger chases them off the island. The boys are invited to the home of Elroy Jefferson, a man whose car they returned in The Shore Road Mystery. They overhear an argument between Jefferson, the owner of Cabin Island, and Hanleigh, who is trying to buy the island. Mr. Jefferson rewards the boys and grants them permission to use the cabin for Christmas

On Max's birthday, he finds a kind of magic mirror in the attic. It can make him invisible. So Max and his friends start playing "now you see me, now you don't." Until Max realizes that he's losing control. Staying invisible a little too long. Having a harder and harder time coming back. Getting invisible is turning into a very dangerous game. The next time Max gets invisible, will it be...forever?