As many longtime Doctor Who fans will tell you, despite hundreds of episodes over the course of six decades, there are a few story types that every era, and every Doctor, has to experience at least once. And perhaps the most famous Who formula of all is the “base under siege story,” in which the Doctor finds themselves in some kind of base, trapped, while some sort of menace runs rampant, or some creeping dilemma threatens to drive everyone nuts. “ The Tenth Planet,” the final adventure of the 1st Doctor (William Hartnell), is an early example, while the 10th Doctor’s (David Tennant) “The Impossible Planet” is a more famous base under siege story from the modern era. But the best story from this subgenre of Doctor Who episodes was released exactly 10 years ago, and the reason it’s still so brilliant isn’t because it’s a perfect base under siege story. It’s brilliant because this two-parter delivers a perfect time travel paradox, which is equal parts whimsical and fatalistic.
On October 3, 2015, Doctor Who Season 9 continued a confident and excellent string of episodes with the now-classic two-parter, “Under the Lake” and “Before the Flood.” Peter Capaldi’s highest point as the Doctor was still several episodes away, later in this season. But, in this two-parter, his 12th Doctor has never been a more convincing or perfect Time Lord, complete with a sneaky downside of what that title really means.
