It was a tiny world without a name. Out beyond the Great Spiral arm, according to the Doctor.

As they sat on the edge of a chalky cliff overlooking a gaseous sea Kim asked the Doctor why they were here.

"For the sunrise," was all he would say.

Ir arrived shortly after. Slowly at first, peeking over the horizon like that cartoon of the man and a brick wall.

It rose like a crimson balloon until it was nearly overhead.

Kim frowned. "Very nice but what am I supposed to be looking at...?"

Just as she finished her question the sky exploded.

It boiled with colours that surged and bled into each other. The whole spectrum was there and then some.

Then came the most jaw-slackening fireworks display Kim had ever seen. It went on for the best part of two hours and defies description in mere words.

When it eventually faded away the Doctor turned to his companion. "In case you're wondering it's caused by an ionic reaction in the atmosphere -" he stopped suddenly, staring at Kim.

She stared back.

They both pointed simultaneously and spoke together. "Your hair!"

The Doctor's normally straggly locks were sticking up and out as if he had stuck his finger in a light socket. Kim could feel her own hair following suit.

She tried to pat it down but it sprang back up like a scolded cat.

Kim put her hands on her hips and waited.

"Does your skin tingle?" asked the Doctor, rubbing his hands together.

Kim nodded.

The Doctor produced his sonic probe and scanned them both.

"We've been irradiated with something." he said, somewhat sheepishly.

Irradiated? She didn't like the sound of that. "What with? Is it dangerous?"

He shrugged. "Back to the Tardis."

*

Kim waited with mounting impatience as the Doctor examined a data screen on the floating central torus in the Tardis control room. Mind you, she couldn't help but smile at the Doctor's errant hair. He reminded her of one of those hairy plastic Gonks she had on the end of her pencil, back at school !

He turned to face her. "Osmatic radiation." he said. "A by-product of the specific atmospheric Ionisation we just witnessed. Quite harmless. I am a clot, Kim. I should have realised there was a reason that place wasn't overrun with tourists."

Kim sighed her relief and patted at her head again. "How long before it wears off?"

The Doctor fidgeted. "Err...26,500 years. Approximately."

"26,500 years!"

"Approximately."

"Approximately!"

"That's the radioactive half life for the Osmatic particles...but we can flush them out fairly easily."

Kim tried to control her breathing. "Oh, goody! How, exactly?"

The Doctor stared at the data screen. "According to this; anaerobic exercise to excrete the shallow irradiated molecules; ingestion of hydroxyl to neutralise the deepest-" he looked up. "- that's alcohol by the way – and stimulation of the venrtomedial prefrontal cortex to produce endorphins which flush out the brain. Laughter would do that."

"So, exercise, booze and a good time? Sounds like a Friday night at the Thamesford Disco, back in the seventies!"

The Doctor snapped his fingers.

*

Kim stood in the centre of the deserted control room feeling ridiculous.

She was dressed in a silky peach dress that style had forgot. Her hair was held firmly in place by a Dylan-cap of the same colour. Off to one side was a small table of various snack foods, including the obligatory cheese and pineapple squares on a stick from her youth. Bottles of beer and spirits stood on another small table.

She was about to call out for the Doctor when the lights suddenly dimmed and coloured shapes skittered around the walls from an invisible glitter-ball.

Kim jumped as deep base music pumped out around her from unseen speakers.

Burn baby burn,
Disco Inferno,
Burn baby burn...

The Doctor strode into the centre of the room from a side arch and stood in front of the goggling Kim.

He was dressed in a white, tight fitting suit, black open-neck shirt and Doc Marten boots. To top it all, literally, he wore a reversed baseball cap to maintain a semblance of control over his weightless hair.

Kim tried to control her welling laughter. He looked so serious...

Then the music changed...

Night Fever, Night Fever...

The Doctor suddenly struck a Travolta-pose.

That did it. Kim screamed, helpless with laughter.

*

For the next two hours they danced.

They bumped to Kenny, they shoulder-dipped to Mud; bounced to the Rubettes.

The beer flowed as did the laughter. Never more so than when the Doctor had to retire for new trousers after attempting the splits to Sweet's Blockbuster. Kim was still crying when he returned.

After a couple of hours the Doctor lowered the music and carefully removed his cap. His hair, matted with sweat, obediently remained in situ. Kim removed her Dylan cap and her bob resumed its natural position.

The Doctor scanned them both with his sonic probe and gave Kim the thumbs up.

They were all clear.

The Doctor turned back to the control panel and Kim felt a pang of disappointment.

But the lights stayed dim.

The music changed.

The Drifters...

It's such a small town girl,
News travels faster than a sigh...

He reached out his hand and she took it. They danced on...slowly.

Like Sister and Brother...

THE END