In this first installment of Planet Krynoid, the world of Planet Krynoid is established.

It's a bit barebones as a story, to be honest. Two people get infected by the Krynoid, and the play follows how the situation deteriorates, mostly due to corruption and selfishness.

The characters are good. The governor is very three-dimensional and while he is definitely somewhat corrupt (his treatment of the Hart family attests to it), he stays sympathetic. The chemovax representative is very punchable, as is the governor's daughter. The hart family is interesting enough, and the two xenobiologists and the doctor are also fine.

The worldbuilding is very effective. The ambiance is good. Yet I sometimes struggled to keep my attention on the story, and I'm not sure why exactly.

The cliffhanger was effective but expected.

Edit: After seeing the rave reviews on here, I decided to relisten Sunlight and Sunset in preparation for Darkness, and I think I found it hard to keep my attention to the story as it juggles a bit too many plots and stories at times. They also kept switching them around at breakneck speed, which made it harder to get truly invested.

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

“SUNLIGHT: KRYNOIDS, CORPORATE GREED, AND A FROSTY FIRST ACT”

Big Finish’s Sunlight marks the opening salvo of Planet Krynoid, a 50th anniversary celebration of one of Doctor Who’s most unsettling villains—the plant-based parasites that first terrified viewers in 1976’s The Seeds of Doom. Swapping English country gardens for a frozen colony world, this latest encounter with the Krynoids delivers classic body horror with a corporate sci-fi edge, blending Alien-esque paranoia with a desperate survival tale.

Set on an icy, struggling human outpost, the story wastes no time plunging listeners into its bleak world. One of the colony’s essential sun satellites is destroyed by a meteorite, bringing with it the mysterious pods that kick off the Krynoid nightmare. Characters come thick and fast, and while the rapid introductions make it difficult to latch onto everyone immediately, the broad strokes of the setting are quickly established: a harsh planet, failing infrastructure, and class divisions between the privileged elite and the slum-dwelling workers.

A GOVERNOR WITH A CONSCIENCE

At the story’s core is Reece Shearsmith as Governor Robert Hodan, a refreshing twist on the usual colony leader archetype. Hodan is not a corrupt official or a cowardly bureaucrat—instead, he’s a man genuinely trying to do the right thing. His immediate instinct is to destroy the alien pods for the safety of the colony, a decision that earns him opposition from those more concerned with profit than preservation.

Hodan’s moral conflict becomes even more compelling when the pods are discovered to possess healing properties—capable of curing disease and extending life. Suddenly, this is no longer just a matter of protocol, but of personal grief, as the possibility of saving his ailing wife throws his principles into sharp relief. It’s a grounded, emotionally resonant dilemma that gives the horror real weight.

CORPORATE INTERESTS, SCIENTIFIC AMBITION

Opposing Hodan is a company representative who wants to monetise the pods, drawing clear parallels with the Alien franchise’s android antagonists—cold, calculating, and ultimately reckless in pursuit of a bottom line. The story doesn't linger too long on these tropes, but their familiarity helps create a sense of unease and inevitability.

Dr Faith Costello is another standout—an ambitious, protocol-driven scientist who truly believes she’s doing something revolutionary. Her curiosity is as dangerous as it is sincere, and her blind trust in the pursuit of scientific acclaim puts her in the classic Doctor Who role of the well-meaning but fatally misguided researcher. She follows orders and procedures, but not always wisdom, which makes her fall from grace all the more poignant.

TENSION IN THE TUNDRA

While there’s not much time to explore the class divide in depth, the worldbuilding is effective: luxury domes for the rich, crumbling ruins from past settlers, icy wastelands, and a growing sense of unease beneath it all. The story’s horror ramps up gradually but surely, beginning with the classic sci-fi mistake—alien pods are found, no one destroys them, and everything starts to go terribly wrong.

Piotr, the first infected colonist, becomes the lens through which we witness the Krynoid invasion from the inside out. His transformation is grotesque and tragic, and the tension builds with each step the base crew takes in trying to contain the threat. The structure cleverly allows the horror to simmer rather than explode immediately, with a growing sense of dread that mirrors the Krynoid’s creeping spread.

INTO THE RUINS AND ONTO THE HORROR

The final act turns from paranoia to full-blown panic. The infection is loose, the colony is on the verge of collapse, and a team is forced to venture into the ruins of the original settlement in search of answers. Here, the audio leans harder into its horror roots—mutations, madness, and plant-zombie attacks that owe more than a little to The Thing and Invasion of the Body Snatchers. There’s even the unsettling suggestion that this has all happened before, with buried records and warnings lost to time.

The ending arrives abruptly, with the Eighth Doctor appearing out of nowhere and leading directly into the next chapter of the saga. It’s a jarring moment, but it also confirms what was already clear: Sunlight is only the beginning. The true devastation is still to come.

📝VERDICT: 8/10

Sunlight is a gripping, chilly reintroduction to the Krynoids, combining body horror, corporate satire, and classic sci-fi paranoia in an atmospheric first act. Reece Shearsmith’s Governor Hodan is a sympathetic, morally complex lead, and the icy setting offers a refreshing twist on the usual Krynoid formula. While the story rushes through its ensemble and doesn’t fully explore its class conflict, it sets the stage for an epic three-part tale with creeping dread, effective horror, and a haunting sense of inevitability. This Krynoid saga is only just beginning—and it's already showing its thorns.

It was a little tough for me to keep track of the characters in this one, but the atmosphere, my God, the atmosphere! Deliciously spooky and unnerving. Looking forward to seeing how things get worse for our poor colony.

I love the expansive cast and the evocative setting, and the story functions very well as an introduction, but a few things were missing for me.

My main issue was I felt the story was proceeding too fast. We flew through all the expected story beats at such a pace that none of them had a chance to really land. I kinda wish this episode had been split into two to really build the tension and dread. I feel this story's strength is its inevitability; we know from the outset that Sunlight is doomed, so I wish we had stewed in that atmosphere for longer.

Secondly and more personally, as someone who loves (and is partly studying) botany: I wish there were more plants in this one! I understand it's unlikely Who will ever dig into the science of Krynoid biology or the biology of plants in general (that moment in the glacier at the beginning was a tantalising tease that hopefully will be picked up on in future episodes) but I personally would have loved to see it. At least we had one xenobotany professor as a main character!

And I was not expecting to hear Eight so soon!

This series opener really does a good job of setting the stakes and worldbuilding. Really intriguing start, a slow one too but I quite like that as it really helps create a good foundation for this series. Predictable ending, but exciting nonetheless!

Big Finish really overdo it when they have kids going "mummy" or "daddy" they make them repeat it like 500 times and it becomes obnoxious. Noticed this in a few releases now!

Very nice world building in this story it sets it up really nicely