The Doctor, Clara and Jack have arrived on the planet of the 456.

Jack disappears.

Moments later the Doctor and Clara are taken...someone has been expecting them...

We have a description of the 456 planet, which I see as being somewhat Mars like. The biosphere, in my head resembles the Eden Project domes in Cornwall, but on a larger scale.

What do the 456 want with them...?

Scene 13.

A desolate, dusty, stony plain. Scattered with boulders and rocks, worn like jagged teeth by a ceaseless dry wind.

Waterless, airless. Grey and deserted.

Not a tree, or any form of life that could be seen. Only emptiness.

The sky above, acrid, dirty looking. Charcoal coated.

Clouds of vapour writhed and seethed. Steam venting from fissures in the ground at their feet.

Occasionally a geyser eruption, would puff momentarily, then die away.

Cratered and pock marked, pitted with past volcanic activity. Long chilled and solidified lava flows, forming flat pathways that meandered here and there.

A billowing mantle of yellow sulphur seeped toxically from the unseen depths.

Pungent. Acidic.

Distant purple mountains rose ahead of them, cone shaped summits, visible through the thin atmosphere.

Far away, on the horizon, a hazy golden sun blazed. It's heat could be felt through the suits.

Picking their way from where the Tardis landed they reached the edge of an escarpment.

Below them the vista opened out.

A vast city.

Tinted orange in the suns rays. It stretched further than the eye could see.

The contrast between where they stood and the opulence before them was marked.

Sparkling, glittering with a thousand points of light.

Enormous domes, made of many interlocking hexagons. Spires of silver like a metal cathedral, soared towards the sky.

Building upon building, majestic, beautiful, tall mirrored exteriors, reflecting the light.

Obelisks, dazzling and magnificent, pointed at the apex, thrusting upward.

Pod like dwelling places, opaque, misty, lined broad thoroughfares.

Small craft could be seen moving from block to block in the distance, floating effortlessly, as if suspended on wires.

The whole place shimmered like a desert mirage.

Under a huge biosphere, an oasis of green could be glimpsed, the twinkle of falling water, the movement of strange, exotic plants in the gentle breeze.

Controlled and managed, the interior a stark contrast to where they stood.

On the plain nothing moved, but the city hummed with life.

The three made their way gingerly down the steep slope towards the conurbation, carefully picking their way around the cracks and fractures in the planet's surface.

They had no real idea of how to enter the city, whether there would be gates, locks, barriers.

Was there military? Check points?

Only time would tell.

Jack strode ahead. The Doctor kept Clara close.

Nothing challenged them as yet.

There was not a creature in sight, as they came to the perimeter.

Then, seemingly from nowhere, amid a swirl of mist, came a disembodied voice...

"Welcome Doctor. We've been expecting you!"

Scene 14

At the sound of the voice, The Doctor turned to Jack. To find him gone.
His eyes tried to pierce the mist.
He felt for Clara's hand and held it tight.
The voice spoke again.
"You will come with me, we are prepared for you."
A slight prod in the small of his back, nudged the Doctor forwards. Clara stumbled beside him and he held her arm, helping her to keep up.
The creature was large. From a glistening body, which looked vaguely reptilian, protruded three heads, each on a long outstretched neck.
It resembled a plucked swan, each head with large piercing eyes.
It's speech, clearly English, but this was not down to the Tardis translating, the creature had clearly done its homework on all the previous visits to Earth.
They were herded onwards, into the city proper, passing along broad boulevards, lined with spectacular buildings.
The Doctor barely had time to register what had happened to Jack. He shot Clara a warning glance, she read the mental message, and remained silent.

They reached the largest building.

The hub of the City.
A heavy door was opened, which led into some kind of holding facility. Passing other doors both to the left and right, along a wide passageway, were glimpses of other beings, apparently working, in what looked like laboratories.

The building was vast. Labyrinthine.

Hundreds of similar cloister like walkways, all leading off in various directions.
Finally, their corridor ended and they were pushed, rather roughly, into a spartan room.

Stark white, almost bare, apart from a bench like apparatus and table, on which were cups filled with clear liquid, that may or may not have been water.
The door closed behind them with a swish.
They were alone.
The light in the room was bright, it almost hurt the eyes. Even through the visors of their helmets.
The Doctor scanned every inch with his hawk like gaze.
Clara moved instinctively, closer to him, still clutching his hand.
A mellow voice penetrated the room from somewhere off to the side.
"The atmosphere of this room is 78% Nitrogen 21% Oxygen plus trace elements. It is compatible to human and Timelord respiratory systems. It is carefully controlled. You are therefore free to remove your headgear."
"How do we know to trust you?"
The Doctor asked.
"You don't." Replied the voice.
They removed their helmets and laid them aside.
"I've come here in peace. I mean you no harm, but I wish to speak with your leader, your king or the elected head of your people."
The Doctor took a few steps towards the wall, looking up, trying to discover the origin of the sound.
"We knew, you were coming. We are surprised it took you so long to find us." Came the reply.
"How did you know?"
"Oh Doctor, we have been awaiting your arrival for many eons. We prepared the way for you. It has taken millennia in Earth years, but that is a short time to us."
"What do you mean, prepared the way for me?"
"For one who considers himself in possession of a vastly superior mind, you are being remarkably slow. All will soon be revealed to you. In the meantime I suggest you rest yourselves."

The voice died away.

Several times The Doctor spoke into thin air, requesting audience with their leader.

But answer came there none.

Silence.

He huffed his frustration. Tried the door.

It would not yield.

"I am an idiot, Clara. I've walked straight into a trap...

your instinct at UNIT headquarters was spot on. They want to use me in some way."

"They won't hurt us though, not if we are useful." She replied, more in hope than conviction.

"I guess we'll soon find out." ...