Humor, romance, clockwork men, and pre-Revolutionary France -- you could be forgiven for thinking that this doesn't exactly sound like the typical episode of Doctor Who. Although The Girl in the Fireplace technically has elements of science fiction, taking place partly on a futuristic spaceship complete with portals into the past, the greater share of the episode is centered around the relationship between the Doctor and Reinette, better known as Madame du Pompadour. Very much a model for Amy Pond's storyline in season 5, the Doctor interacts with Reinette throughout her timeline, starting from her childhood. It's a particularly effective way to explore their relationship, only helped by the tremendous amount of chemistry between the two actors (with good reason -- they dated in real life).