The Doctor lands the TARDIS at exactly the right spot to drop Tegan off at her job, and even has her there a bit early... 315 years early to be exact. It's 1666, and they're in a rather deserted bit of English countryside. There they meet lovable rogue Richard Mace, an actor-turned-highwayman with an interesting grasp of situational ethics (breaking and entering: bad; stealing: fine), but fortunately the Doctor and company are around to teach him their own superior ethics (breaking and entering: fine; stealing: bad). So the Doctor sets it all on fire.