Before Light and Time and Space and Matter (White Darkness) »David McIntee's White Darkness, the fifteenth New Adventure, features the TARDIS crew in early 20th century Haiti during the events leading up to the American occupation. It also has them fighting Cthulhu and zombies. So it's a bit ambitious. The Cthulhu stuff is what it's best known for these days, since that becomes a bit of a theme for the New Adventures, but it's just as notable for introducing McIntee, who went on to write scads more books, and his research-heavy historical style....
