The Marian Conspiracy marks a major turning point for Big Finish’s Monthly Adventures—and for Colin Baker’s Sixth Doctor. Jacqueline Rayner’s confident, tightly structured script gives Baker the material he never quite got on television, allowing his Doctor to be witty, warm, and wonderfully sharp without the abrasive edge that once made him a harder sell. The story balances historical detail with compelling character work, and never overstays its welcome. It’s the first time the range really feels like it knows what it’s doing, and the result is a polished, engaging audio drama that still holds up brilliantly.

At the heart of its success is the introduction of Evelyn Smythe, a sharp, no-nonsense history professor brought to life with irresistible charm by the late Maggie Stables. Unlike many companions before her, Evelyn doesn’t scream, swoon, or ask too many questions—she challenges the Doctor intellectually and morally, and their chemistry is immediate. Their opening conversation alone is a joy to listen to, setting the tone for a partnership built on mutual respect and gentle bickering. It’s refreshing to hear a story where so much of the drama comes from the characters themselves, rather than technobabble or alien threats.

Though it plays with a sci-fi conceit—Evelyn’s existence being threatened by a time anomaly—this is essentially a pure historical, and one that uses its setting with real intelligence. Tudor England is rendered vividly, and Queen Mary is written as a complex, sincere figure rather than a stock villain. A standout moment sees the Doctor challenge her beliefs without resorting to moral grandstanding, a testament to the script’s subtlety. By the time the story finishes, it’s clear that Big Finish has found its voice—and that the Sixth Doctor has, at long last, found the companion who brings out the best in him.