Thworping through time and space, one adventure at a time!

THE KEY TO MANY WORLDS – MARCO POLO RETURNS, IRIS WILDTHYME TAKES OVER, AND SIX GETS SWAPPED

The Key to Many Worlds brings together a most unexpected trio: the Sixth Doctor, his steadfast companion Constance Clarke, and – from the distant reaches of the First Doctor’s era – Marco Polo himself, now older, wearier, and grappling with the end of his adventures. Terry Molloy, more famously the voice of Davros, slips into Marco’s sandals with surprising ease, offering a take on the famed explorer that’s equal parts melancholic, dignified and quietly craving the thrill of one last ride.

Set primarily during a caravan journey from Baghdad to Venice, the story beautifully evokes the atmosphere of Marco Polo (1964), even referencing its structure through Marco’s diary narration. This alone is a delightful throwback, and the decision to explore Marco in his twilight years rather than his prime offers a genuinely fresh approach. He’s no longer the wide-eyed traveller; he’s a man burdened by nostalgia and unmet expectations, with little left to believe in – until fate (and the TARDIS) tosses him back into something bigger than himself.

DOCTOR, MEET DOCTOR… SORT OF

The heart of the story is a body-swap farce wrapped in a historical cloak, as the Doctor finds his mind trapped in the flamboyant, bewitching Iris Wildthyme – and hers in his. Iris’s explosive entrance as a mystical enchantress doing magic tricks in Baghdad’s backstreets is pure Katy Manning, delivering chaos, charm, and confusion in equal measure. And yes, even if you’re not usually a fan of Iris, it’s hard to deny the infectious energy Manning brings. She goes toe-to-toe with Colin Baker’s larger-than-life presence with absolute glee.

The resulting body-swap is where the real fun begins. Manning doing her best impression of Sixie is inspired and surprisingly accurate – their voices now closer in age and register adds to the illusion. Colin, meanwhile, relishes the chance to go full Iris, letting loose with a mischievous vocal performance that lets him explore the sillier side of his Doctor. These two veterans clearly had a blast, and it’s a joy to listen to.

In fact, at times, The Key to Many Worlds feels like a screwball multi-Doctor episode, with Six and Iris bickering, bantering, and out-camping each other at every turn. The scenes between them are pure chaos – a tone that works wonderfully in the first half, even if it becomes a little overstretched by the end.

CONSTANCE IN THE BACKSEAT

Sadly, Miranda Raison’s Constance Clarke doesn’t fare quite as well here. She’s sidelined for most of Part One and only steps up meaningfully after the body-swap is revealed, trying valiantly to convince Marco that the Doctor isn’t himself. Her scenes with Marco are strong – especially given his nostalgic comparisons to Barbara Wright – but by Part Two, she’s again nudged out of the spotlight, with little to say or do while the louder characters dominate. It’s a real shame, as Constance is a sharp, capable companion who deserves more than just standing in the background while everyone else shouts.

A NEW DIMENSION TO MARCO POLO

What sets The Key to Many Worlds apart is how it uses Marco Polo not just as a nostalgic callback, but as a character undergoing real emotional change. His dynamic with Tonio, his loyal (and romantic) companion played by the late Anthony Townsend, adds new layers to Marco’s identity. This is Doctor Who exploring the LGBTQIA+ dimensions of history that classic TV would never have dared to approach, and it’s done subtly and sensitively.

Tonio serves both as a grounding influence and as someone quietly trying to reawaken Marco’s passion for life. Their relationship adds emotional weight to Marco’s internal struggle: he’s tired, disillusioned, and no longer the hero he once was. His moment of fury at the TARDIS – demanding that the Doctor take him back to his youth – is a striking character beat, as is his disappointment upon reaching Venice and finding no one remembers him. History has moved on, and heroes fade.

A TALE OF TWO HALVES

Despite its inventive setup and strong character beats, the story does lose momentum. Once the caravan reaches Venice, there’s a sense of deflation. The tone drifts from playful chaos to something more subdued, yet without raising the stakes or introducing a compelling new conflict. It’s as if the body-swap and Marco’s arc have run their course, and all that’s left is a quiet fizzle of a conclusion.

Still, the final scenes, while lacking drama, carry a certain emotional beauty – Marco finding peace, the Doctor and Iris mutually parting ways (again), and the sense that another chapter in time has gently closed. It's less an explosive climax and more a soft curtain call.

📝 VERDICT: 79/100

The Key to Many Worlds is a charming, if slightly meandering, entry in The Cosmos and Mrs Clarke. It thrives on its inventive premise – a reunion with Marco Polo, a body swap with Iris Wildthyme, and all the comic and dramatic possibilities therein. Terry Molloy gives Marco real weight, and Colin Baker and Katy Manning clearly revel in the opportunity to swap personas. While the story flags in its latter half and leaves Constance frustratingly underused, there’s plenty here for fans of historical Doctor Who, whimsical mischief, and character-driven storytelling. A fond, funny, and bittersweet oddity in the Sixth Doctor’s ever-growing Big Finish tapestry.