In 2269, Ensign Jackson and Yeoman Lily Lancer were off duty together in the recreation room. The Enterprise was approaching the Amusement Park Planet for shore leave, and he looked forward so much to beaming down that he had writer's block. He found himself explaining to Lancer that rather than lacking in ideas, shore leave had overwhelmed him with ideas.
Jackson had actually been fantasizing that he was Samuel Clemens in a daydream about an 19th century American river adventure. As his story began, Cairo steamboat captain Benjamin Lee and his crew were in a rush to transfer critical vaccines to Paducah, Kentucky. Clemens was the ship's experienced pilot, who knew where to find every hazard during the route, but thought to check the river at that moment anyway, in case there was a hidden sandbar. (TAS - Log Three novelization: Once Upon a Planet)