7

From a distance the Doctor watched as a group of about twenty men loaded the TARDIS on to the back of a large low wagon pulled by four sturdy oxen. Then it trundled away through the trees.

‘Well, it was just a theory,’ he said.

He’d fought with the man in the river for a long time, but finally the poor human had succumbed to the cold and had been washed away to Valhalla.

The Doctor had managed to fish himself out of the river and had stood dripping on the riverbank, but within minutes the water had begun to freeze, threatening to turn him into a living ice sculpture.

The cold didn’t worry him unduly. Given that his normal body temperature was way below human levels, the dip in the river had been no more than refreshing, certainly not deadly.

But it was a nuisance being damp and icy, so he began to walk briskly back along the bank, trying to pick up Jo’s trail. One of the advantages of having a binary vascular system was that he could always pump his blood faster than normal if he chose to, raising his body temperature at will. Very soon his clothes were steaming as he walked along, and in twenty minutes he was as dry as a good martini.

‘As I always say,’ he said, ‘two hearts are better than one.’

He soon came back in sight of the waterwheels and the bridge, and hesitated for a moment. He had to find Jo. But something wasn’t right about these waterwheels, and he knew he should investigate.

He hesitated a little longer. The most important thing was to find the spear. But then there was Jo. Jo Grant. Loyal, funny, quick-witted Jo. If anything happened to her … He’d had other companions before, of course, and all wonderful people, in the various weird ways humans could be, but none of them was quite like Jo …

‘Five minutes,’ he said to himself.

A quick look at the waterwheels and then find Jo. If they’d wanted to kill her she’d be dead already, and five minutes wouldn’t help that.

He crossed the bridge to the far side of the river, and as he approached the closest waterwheel he saw something in the distance they’d missed before.

Through the forest, up and away on a hill, was a clearing, and in the clearing stood a wooden temple, towering and vast.

He felt a strong urge to go and take a look; even from this distance and looking through the trees he could see it was covered in fantastic carvings that he longed to examine, but Jo had been taken the other way, and there were the wheels, and the spear, and …

He hurried on.

There was no one in sight, but he approached the first waterwheel cautiously – being shot at and dunked in a river was quite enough fun for one day.

The wheel was a heavy undershot device: a long wooden leat channelled water from the river to the bottom of its fins, which turned constantly in the flow.

He moved on to the next wheel, and the next, and now, in the far distance, he heard the sounds of axes and saws, of wood being chopped in the forest. He squinted towards the direction of the sounds and watched as part of the forest trembled, and then a gap appeared in the canopy as a tree came down.

‘They’re making more …’ he said, wondering why they needed all these wheels, all this potential power – power that was useless unless it was feeding something.

But what?

The axle of each waterwheel entered a wheelhouse, and the Doctor approached the nearest one. The door was locked; a big iron keyhole was set into the heavy wood.

The Doctor pulled his sonic screwdriver out of his pocket and, once inside, his eyes widened.

There was no primitive set of cogs and drive-shafts, no trip-hammers or cam-wheels. No milling or grinding stones. Instead, the axle of the wheel went straight into a large metal box, from which heavy-duty electrical cable emerged and then disappeared into the dirt floor of the wheelhouse.

Neither the cable nor the box looked like they had anything to do with Earth in the second century AD.

It was as he’d left the wheelhouse that he’d heard the snort of an ox from across the river, and that was when he’d seen the TARDIS being towed away.

The Doctor put his head down and made for the bridge.

‘Hang on, Jo,’ he said. ‘Hang on.’