In the book "Mystery in the Sand" by Gertrude Chandler Warner, the story revolves around a group of children who uncover an intriguing mystery. As they delve into their adventure, they discover connections and clues that lead them to unexpected revelations. The plot emphasizes teamwork and the idea that collaboration often leads to greater insights, highlighting the theme that sharing thoughts can unveil deeper truths.

The quote "And I thought I was the only one who put two and two together!" reflects a moment of realization shared by the characters, illustrating the joy of discovering that others are also piecing together the same puzzle. This sentiment resonates with the notion that individuals often find comfort in knowing that they are not alone in their thoughts, reinforcing the story’s core message about friendship and shared experiences in solving mysteries.