'Ancient castle. Ancient tomb, the legend.'

The Doctor and Graham stand staring up at Bluebeard's castle. "Funny looking castle," says Graham with some puzzlement. "No way in as far as I can see, and no people about. Where are the soldiers? … Anyhow, I thought Bluebeard was a pirate."

The Doctor brandishes her sonic screwdriver at the castle. "Not a castle in the usual sense, in fact something very, very strange. … Do you know the legend, the fairy tale, of Bluebeard and his wives?"

"The wives go into rooms he has forbidden them – a bit like Beauty in 'Beauty and the Beast' – so he kills them; one after another."

"That's the story: his brides open locked doors and discover his secrets, so he kills them. But we can't assume that is even half-true."

"Do you believe those people: that this Duke Bluebeard carried away a young woman, Judith, and brought her here to this … this dismal place?"

"I do. They say she went willingly, even though she had barely met him. That is not normal human behaviour."

Graham looks unconvinced. "So he probably isn't a serial killer, and she went of her own accord. Why should we stick our noses in, legend or no?"

"Two reasons. Firstly, I suspect mind control. Have I ever mentioned hallucinogenic lipstick? No? Someone I … um … used to know could convince people of anything just by kissing them. Bluebeard may have used something like it to persuade Judith to run off with him."

"And the second reason?"

"That castle has alien technology or I'm no Time Lord."

"OK, I'm with you. What's the plan?"

.***

Darkness and silence; then a noise never heard there before: the Tardis materialising. The light on top illuminates nothing. The door opens and Graham puts his head out. "It's pitch black and rather chilly; I reckon you've landed us in the dungeons."

The Doctor steps out past him and claps her hands. "Hear the echo; we are in a large space; this must be the main hall of the castle. Smell the air, what do you make of it?"

Graham follows her out; the light from the wide open Tardis door shows up only the immediate surroundings. He sniffs the air. "I can't smell anything."

"Nor can I. All Earth buildings at this time should be smelly: people, animals, cooking, whatever."

"And where is everybody? The silence is creepy. Perhaps the place is empty?" Graham finds he is whispering; the place, empty or not, is unsettling him. The Doctor dives back into the Tardis and returns at once with two torches, she gives one to Graham and shuts the Tardis door. The narrow beams from the torches pierce the dark, and show rough stone walls and a high, vaulted ceiling. The floor is bare, icy-cold flagstones, and they see no furniture at all in the cavernous room. The only way out appears to be a row of doors; Graham counts seven. He gingerly tries one, but it is locked.

The Doctor attempts to unlock it with her sonic screwdriver, but to her surprise it does not open. "These doors are not what they seem," she mutters, intrigued.

"Didn't you say that thing doesn't work with wood?" queries Graham.

"It doesn't, but these locks are metal."

"We could try knocking," Graham suggests.

"All this technology and I overlook the obvious," she sighs, and points out that on the wall next to the left-most door there is a large gong.

Graham is puzzled and wary. "That wasn't there a minute ago. I'm sure it wasn't."

Nevertheless, she takes the hammer and strikes the gong with it. It is startlingly loud, and the deep, discordant clamour reverberates around, dying away over a period of several seconds. The following silence is so profound that they can hear their own breathing. "Am I imagining it or is it not quite as dark," whispers Graham.

"Shush, someone is coming."

Though he does not carry a light, it seems to grow a little lighter as Duke Bluebeard walks slowly towards them. He comes to a halt in front of the Doctor and stares into her face. It is difficult to read his expression through his thick beard, but his voice is sorrowful and without anger. "You have entered my castle without leave. Here I am master. You should not have come, you or your servant. Your witchcraft will not avail you."

Graham bridles and responds with flippant sarcasm: "Nice place you've got here."

"Do not joke: my castle is dark, cold, gloomy. It is my burden."

"Yet you brought Judith here," says the Doctor. "We have come for her. Where is she?"

"She is beyond your help or reach; beyond mine too. The castle has her."

"Have you harmed her, is she alive?" asks Graham angrily.

Bluebeard responds slowly, as though in a daydream. "Alive? … Yes, my wives are all living. … I wished them no harm. … The castle has them, nothing can be done: the circle cannot be broken."

There is a glint in the Doctor's eye. She says, "You said you are the master here. But you are not, are you! Tell us what you mean: 'the castle has them.'"

"No: I keep my secrets."

"All the girls you brought here, they're behind these doors? Which door?" demands the Doctor, angry.

"The doors are locked against you. Try your witchcraft: open one if you can."

"Give me the keys!"

"Never!"

"Doc," says Graham. "I have a hunch the doors might open if you tackle them in the right order."

She studies Bluebeard for his reaction to this suggestion. "It's worth a try. Which door first?"

It is Bluebeard who answers, much to their surprise. "This is the first door, do not open it, for you will not like what you see." The Doctor wields her sonic screwdriver and the door springs open. She and Graham both gasp at the terrible sight within. "Mighty is your magic! It has opened the door to my torture chamber."

The Doctor quickly scans it. "It's not real: it is a psychic projection - alien technology." She closes the door, moves to the second, and looks at Bluebeard for his reaction.

He nods grudgingly. "This is my armoury, full of weapons." The sonic screwdriver reveals arrays of ancient weapons, rusty and blood splattered.

They move on to the third door and Bluebeard is silent. The Doctor opens the door and in a yellow glow they see stacks and piles of coins, silver and gold, and jewels of many kinds. "Another psychic projection, I hope we see something better in the next doorway."

They do: it is a garden in fabulous bloom. "That is better," says Graham, "and with each door the castle's getting brighter."

The Doctor is not so pleased. "Notice the red blotches here and there: bloodstains. … Seven doors; seven colours of the rainbow. We have had red, orange, yellow and now green. The fifth should be blue."

While Bluebeard stands aside, the fifth door is opened to reveal great vistas of lush meadows, rivers, wooded hills, forests and mountains. "Behold my mighty dominions," boasts the Duke.

"Hah, you can see as good at any cinema near you," counters the Doctor. "This is just a cinematic projection. Simple, late twenty first century technology."

"Isn't this the fourteenth century?" asks Graham.

"Next should be indigo. What panorama is behind this door?" continues the Doctor, hurrying to the sixth.

"No! No!" exclaims the Duke, but he makes no move to stop her. A great lake is revealed. "My tears, the lake of tears I have shed. No more. No more. The last door should never be opened! NEVER!"

"That is because your wives are hidden there, isn't it?"

"Go no further," he begs. "There is no going back if the final door is opened."

"Graham, what is your hunch? Do we open the seventh door or give up?"

"Oh, we open it all right; those women are trapped behind it I'm sure, but there are a couple of things we should do first. You've been scanning everything in sight with that sonic thing of yours, except for one: you haven't scanned Bluebeard himself."

"Good point; easily fixed. What else?"

"We should find the Tardis first, it isn't where we left it and we might need to leave in a hurry!"

"Excellent thinking: but don't worry, it's exactly where we'll need it."

Bluebeard interrupts, "Do not think you can leave by any means, once the seventh door is opened. There is no hope. Point your scanner-light at me and learn the truth of it."

The Doctor obliges, and then spends time studying the sonic screwdriver readout while both Bluebeard and Graham watch her closely in agonised silence. Finally she straightens up and asks, "Duke Bluebeard, how many doors are there?"

Bluebeard answers without hesitation, "Seven doors in my castle. The seventh door is the last, it must never be opened."

She smiles. "No, it is not the last, there are eight doors now." And there, at the end of the row is the eighth door, the door of the Tardis. Bluebeard staggers back, nonplussed. Swiftly, the Doctor uses the sonic screwdriver on the seventh door, which swings slowly open. The four young, beautiful 'brides' of Bluebeard slowly step out, one by one. All exquisitely dressed, all with eyes closed, sleepwalking in a sleep from which they cannot wake. The Tardis door is opened and with Graham's help the four are shepherded inside.

Only when all four brides are inside the Tardis does Bluebeard move. "Now I understand," he says. "The spell is broken. Thank you, Doctor."

"Broken?" she says. "No, I have merely got around it. You know how it may be broken for ever, but I cannot ask you to do it."

"I am sick and weary of this half-life; I would break the spell: take me with you." Whilst he is saying this the light has faded to darkness, leaving only the light from the Tardis. A cold wind blows around them, rising to a howling gale and it feels as though the whole castle is shaking. "Quickly," says Bluebeard, "save yourself, go through your door and escape the wrath of the castle."

"Come with us and it could kill you," says the Doctor, but Bluebeard strides into the Tardis regardless. Now everybody is inside the Tardis, and the door is closed, cutting off the horrible screeching sound now being made by the castle. The four brides are as still as statues, the Doctor is looking grimly triumphant and Graham perplexed. Bluebeard is holding his head in his hands and groaning. "Bluebeard which bride is Judith?" the Doctor demands, and Bluebeard points to her before collapsing unconscious.

The Tardis arrives at the home of Judith's parents and the Doctor leads her out, still somnambulant, and gives her into the hands of her mother, with reassurances that she will soon recover. Back in the Tardis the Doctor brushes aside Graham's plea for explanations, telling him that the other three brides have been under the influence of the castle too long and need urgent expert attention. The Tardis takes them to New New York Hospital and the Doctor hands the three brides into the care of the Sisters of Plenitude, while Graham remains with Duke Bluebeard, still unconscious.

"What about him, Doc, he's pretty sick?" Graham asks when the Doctor returns. "Why isn't the hospital taking him as well?"

"Because the Sisters of Plenitude only treat human patients. He may look human but he is a simulacrum, and his physiology is totally alien.

"What'll happen to him?"

"He will die and be at peace. It is what he has wanted for a long time."

"There is a lot I don't understand."

"I only realised when we got inside it, that the entire castle is a living thinking alien being. It is a predator, arriving on a planet and using mind control to exploit the creatures it found there. How it got to Earth I have no idea, but it has been struggling to survive here. Anyhow, it grew Bluebeard as a lure to bring intelligent young people into itself. This Bluebeard is semi-autonomous: able to think and act on its own, but subject to the mind control of the castle. A miserable existence for an intelligent creature!"

"Why all this business of the doors?"

"My guess is that they were a test: the castle observed their reaction to them in order to decide whether to keep them."

"A nasty business. Why didn't this mind control affect us?"

"It did: where do you think those hunches of yours came from?"

"Heck. What happens now?"

"The castle will die, it will be just a pile of rubble, and that rubble will crumble and there will be nothing to see. But the name 'Bluebeard': that will survive as legend and as fairy story. And each generation of storytellers will twist the story to suit their own prejudices and beliefs: it is what humans do."

Graham laughs. "Here's my take on it: Bluebeard is desperate for love, but is under the thumb of his domineering, selfish mother, and she, the castle, is the ultimate mother-in-law from Hell."

"I'll take you home."

THE END