Mickey and Huck are two characters from the classic novel 'The Adventures of Huckleberry Finn' by Mark Twain. The novel follows the journey of a young boy, Huck, and his friend, a runaway slave named Jim, as they travel down the Mississippi River. The two characters, Mickey and Huck, are best friends who embark on a series of adventures together. The crossword solution FINNS is a reference to the novel's title, as it is a play on words for the author's last name, Twain.