This happened to me some years back when I found myself in a different century mentally. I was watching a movie The Message starring Anthony Quinn. As per the dictates of Islam there no image of the Prophet but you can feel the presence.
A scene was being shown in which the people are anxiously waiting for the arrival of Prophet Muhammad (Peace be upon him) to the city of Madina. Before that the Prophet hides in a cave with a trusted friend to escape from getting killed by the unbelievers of Mecca.
A spider makes his web over the entrance to the cave. The unbelievers are misled by the spider’s web and leave. From there the Prophet makes it safely to Madina.
I found myself really craning my neck to look into the distance for his arrival. My heart was thudding. I had totally forgotten that I knew the outcome, and the story. As the people shouted that they could see him, tears of relief and joy slid down my cheeks.
My world had suddenly gone centuries back.
Take two main characters from two different books (either fiction or nonfiction) and introduce them to, or have them meet, each other. What would happen next?