"Governor Morgan has gone crazy." That was the report that HQ had received from Alpha Centauri B. They decided that it warranted investigation and looked for a commander to lead the mission, but they only chose me because the senior officer was sick. They still didn't really trust me because I was black, female and only twenty six. But I had the qualifications and was officially Commander Catherine Clark, though everyone called me CC.

The day we left, I walked across the tarmac to the spaceship, shining on its launchpad, with a mixture of nervousness and pride. My lieutenant, John Wood, lumbered along beside me, making me look like a child in comparison. It took a week to get to Alpha Centauri B, even through hyperspace, and I felt pleased with myself when we landed at the spaceport. The journey had gone without a hitch and I was beginning to think this trip was going to be a triumph.

The spaceport lay at the edge of the Occidental Plane, with a range of mountains to the east, but we headed west towards the city of Lincoln, in an electromobile. It was spring here, the temperature was pleasant, and I could see strange plants with pink tendrils. However, much of the land was cultivated with varieties of potato, and fodder crops which were being grazed by small cows. There were gangs of men working in the fields. John stopped the electromobile and looked at them through the binoculars.

"There's something odd about those guys, CC." He handed me the binoculars.

I noticed two things. Firstly, all the men were more-or-less identical – white-skinned and stockily built - instead of the usual mix of racial types. But the fact that worried me was that they were all shackled, with enough chain to allow them to work but not run away. Now slavery bothered me, not only because it was against Galactic Ordinance 5, but because I had been told some of my distant ancestors were slaves. It made me uneasy.

"Let's stop at the nearest village, ask some questions," I said.

"Our instructions were just to go see Governor Morgan," John reminded me.

"Yeah, but I’m the commander. I can exercise my judgement."

He shrugged his big shoulders. He was a loyal guy, though not the brightest.

We stopped in a small place with a few shacks and a store with a charging point for the electromobiles. I wandered into the store to talk to the guy who worked there. It wasn’t much of a store, just a few shelves displaying the usual mix of canned drinks and vegetables, batteries and coils of wire. A man ambled from the living quarters, and I saw he looked like one of the slaves, with heavy eyebrows and a wide nose.

I paid for the charge and asked "D'you know anything about the men in the fields?"

He looked down at the counter. "It’s nothing to do with me, Ma'am." Then he hurried back the way he came.

"We’re not going to get anywhere with him," I said, as I rejoined John in the electromobile. "But we better keep our eyes open."

As we drove off, I looked back and saw a series of puffs of smoke from behind the store. Maybe the store guy was just burning his rubbish, but it looked like a signal to me.

We arrived in Lincoln to find an undistinguished town, where most buildings were single story, of locally-made bricks. One building towered over the others, and was stone with narrow windows and crenellated walls, like the ones you see in picture books. This was obviously the Governor's residence, though why he wanted to fortify it wasn't clear to me. The town was full of guards with black uniforms and guns, and they all looked like the man in the store.

"Those guards worry me," I told John.

He nodded. "I just hope they're not trigger happy."

We walked up to the big doors of the Governor’s residence, presented our papers, and were shown straight in. A steel door closed behind us with a clang. As we walked we passed locking doors and guards at every turn. I was beginning to feel nervous and I could sense that John was too, from the number of times he looked around. When we reached a corridor with a red carpet, a guard took our papers, asked us to wait and marched away, leaving John and me sitting on plush chairs.

"How do we get out if we have to?" John whispered.

"We look for air vents, pipes, waste chutes," I replied, with a confidence I didn’t feel.

After a few minutes, the guard returned, showed us into a laboratory, and joined a group near the door. I recognised many of the instruments, including centrifuges and electron microscopes, but some were new to me. A man wearing a white coat was working at a microscope, and I knew immediately that this was the Governor. He was tall and wiry, with a domed forehead, and the way he ignored us and continued with his studies suggested the obsessive. When he turned and looked at us, I found the directness of his gaze disturbing.

"Come and look at this," he said to me, when he had finished his scrutiny.

I approached, looked at the slide and recognised the spider web form of nerve cells. "Neurons," I said.

"Yes, and the source of our intelligence. I'm very interested in intelligence. How it's inherited and how it operates. Would you say you are intelligent, Commander?"

"I hope so, Sir."

"And you, Lieutenant?" he asked John.

"I'm not as clever as the Commander," John said, with engaging honesty.

"What I've found is that the cleverer a person is, the harder they are to control," said the Governor, giving me that direct gaze again. "Very clever people tend to be unpredictable, rebellious even. So, for most tasks, give me the slow but steady mind. So we breed them."

"Breed them, Sir?" I asked.

"We isolated Neanderthal DNA and produced a number of cloned Neanderthals. Then we let them breed, with some restrictions."

"So those guards are Neanderthals?"

"They are admirable. They are intelligent enough to obey instructions, but not to question them."

"And the men in the fields? The slaves?"

He frowned. "Even within a controlled population you get some who are ...difficult."

"So those are the cleverest ones?"

The frown grew savage. "Any that are too clever, we eliminate."

"But you can’t do that, Sir!" I gasped, shocked. "They're people. You can’t just kill them off."

He raised an eyebrow. "They are not people, Commander. They are not human. They are sub-human. Animals."

I looked into his grey eyes and saw no pity. "And are you happy that I report this back to HQ?"

The Governor gave a nod to the guards stationed by the door. "HQ are so tied up in their rules they have lost all sense of vision. You are staying here until tomorrow and then I mean to experiment on your brain."

Before I could react, the guards seized us and bundled us out of the laboratory. John struggled against his captors, but I walked quietly and tried to remember the route we were taking. I noticed that the corridors became smaller and the windows vanished altogether. I guessed that we were heading underground, but had no way of knowing in which direction. At last, we were pushed into a windowless room and the door was locked behind us.

John threw himself at the door with such force that he reeled back, stunned and flopped down on a mattress. In an attempt to keep myself calm, I looked round the room, but I saw nothing that brought me any comfort. The door was metal, the walls and floor concrete, the only furniture a couple of matresses. I worked my way round the walls, tapping the concrete, looking for air vents and cracks; then repeated the exercise on the floor. I wasn’t tall enough to reach the ceiling but John stood on tiptoe and examined it. He shook his head.

I sat on a mattress, and assessed our situation. Although I had been trained to deal with a variety of threats, our prospects looked poor. "Any ideas, John?"

"We jump a guard."

"We'd get as far as the first set of doors."

"That's better than being here." John sat down and covered his face with his big hands.

"It might be better to talk to the guard."

"You heard what the Governor said. They’re stupid."

"Are they?" I lay back on the mattress and thought. "From what I’ve read, the Neanderthals weren't that stupid. These guards just haven't known any other life. Perhaps they can be influenced."

John shrugged. "I suppose it’s worth a try."

I tried to make myself comfortable on the mattress and settled down to wait. I told myself to be positive, to remember that we were sent on a mission to talk to Governor Morgan and carried out our instructions correctly. There was no way we could have anticipated our present predicament. Yet I could imagine the old hands back at HQ shaking their heads and muttering that it was foolish to trust such a mission to a young woman. I wondered if John felt the same way.

A couple of hours later, we heard boots outside and a guard entered with a tray of food. I stood up to take it.

"Can I ask your name?" I said, in an attempt at charm.

"I’m number 357."

"Where I live everyone has a proper name and is free to..."

The guard turned away to look back into the corridor, then spoke in a murmur. "Come with me."

It seemed that we had nothing to lose, so we followed. He led along passages that were meaner than those on our way in, and past rooms that were dark and silent. There were few people around, and when we met another guard, our escort grunted a greeting and passed on. He reached a heavy door and motioned us to stop. He opened it a little and peered out into a compound that was lit by powerful lamps. With his head thrust forward and heavy brows clenched together in concentration, he seemed as much ape as man. He looked in all directions and listened.

When he was satisfied, he turned to us. "See that electromobile? Run to it."

Sensing that we were being offered an escape, I ran, followed by John. Our guard outpaced us, scrambled in and started the motor.

"Get on the floor," he said.

We threw ourselves on the floor as the guard drove up to the gates and was waved through. He accelerated away and I was impressed by the speed and accuracy with which he drove.

"Where are we going?" I asked.

"To the rebels."

"There are rebels?"

"Red Rock will explain."

"Thanks for getting us out of that place, mate," said John.

The guard nodded, and we drove on in silence. As soon as we left Lincoln, the town lights stopped, but the road was lit by the planet’s two moons. After a while I saw the floodlights of the spaceport buildings some way ahead, but we turned off the road onto a dirt track, which grew rougher and rockier as we headed for the mountains. We entered a valley, surrounded by cliffs which shone a silver-blue in the moonlight. The guard stopped the electromobile and got out.

"We walk," he said.

As we walked up a path which climbed alongside a stream, I noticed how sure footed our guide was. He darted among the rocks. It made me reflect on the abilities of the Neanderthals. It was clear that they could drive electromobiles and handle weapons, and they were strong and agile. On the other hand, our guide had spoken little, although he clearly knew the Common Speech of the galaxy. It seemed odd that our safety depended on the sense and goodwill of a member of a race that had died out on earth. We had thought Neanderthals inferior, but I was coming to doubt that verdict.

Our guide clambered up a slope and disappeared. Following him, I stumbled over the lip of a cave half hidden by rocks. In a minute, John and I were standing in a large cave, facing a group of Neanderthals. They watched us with suspicion, but without hostility. I bowed, with my palms held out, so they could see we weren't armed. A man emerged from the crowd, taller than most of the Neanderthals, and broad shouldered.

"I’m Red Rock" he said. "You are welcome, Commander Clark, Lieutenant Green."

I blinked. "You know who we are?"

"We have people watching."

"Will you tell me what’s going on, Red Rock?"

"In the morning. For now, we sleep."

We were shown to the back of the cave, where we found wooden benches, covered with rugs. I must have slept because the cave mouth was full of sunlight when I woke. A fire was burning and the Neanderthals were squatting around it. Apart from the fact that they wore clothes of some rough material and leather boots, they looked like the archetypal image of cavemen. John and I were invited to sit by the fire, and handed hunks of bread.

Red Rock faced us across the fire and started talking. "I want to tell you about our people. We're not sure how we came to be in this land. There are stories that the Governor bred us to work for him but I don’t know how."

I nodded. "I think I do."

"Anyway, we have to work and if we refuse, we are made slaves, or killed. We're taught practical things, but not how to read and write, though we know the humans can. But we're not stupid. We would like to be free, to live as we want to. And some of us have got together here, to work out how we could win our freedom. And we have friends – people who work for the Governor but pass on messages to us. We know what's going on."

"What is going on?" I asked. "What is the Governor up to?"

"He is building an army. An army of our people – Neanderthals he calls us. We don't know what he wants to do with that army but most of us don't want to fight for him. We regard this as our home and we would fight to protect it, but we don't want to fight in some far off place." He broke off and looked at me. "I gather you come from another planet."

"We do, and we’d like to go back there. John and I were sent to find out what the Governor's doing. We thought we were going to die there until one of your men rescued us." I looked round to see if I could recognise our driver, but failed. "I’d like to thank him."

"We'll help you to go back but, in return, we want you to do something for us. We want you to tell your people about us. Tell them we want our freedom but we need help against the Governor and his supporters. Will you promise to do that?"

I looked round the circle of faces in the firelight and wondered how much help HQ would be prepared to give this race of Neanderthals. They might not be regarded as human. On the other hand, the prospect of the Governor raising an army might be enough to persuade HQ to act. "I will do what I can," I said.

"And you, Lieutenant Green?"

"I promise, Sir."

I noticed the 'Sir'. It looked as if John, at any rate, accepted Red Rock's authority.

Red Rock nodded. "They’ve put a guard on your space ship, but some of them are friends of ours. The rest we can deal with. We'll leave before midday, because we'll need to walk and it'll take some hours to get there. Are you ready for a long walk?"

As the sun rose in the sky, we joined a group of Neanderthals filing out of the cave into the valley below. In this light, we could see every fold of the cliffs, and I realised that the rebels had chosen their hiding place well. The cave would have been almost impossible to find in this rugged country. The Neanderthals walked fast and almost in silence. I found it difficult to keep up, but we stopped a couple of times to pass around dried meat and flasks of water. The sun was setting by the time we approached the spaceport. We stopped among some hillocks and watched the guards patrolling.

Red Rock waited until the sun set, then we crawled forward, keeping in the shadows until we reached the fence. Some of our companions produced wire cutters and, in a few minutes we were through and running across the tarmac. The guards round our spaceship hesitated, some dropped their weapons, but others started firing. Our new friends started firing back and some of the guards fell. In the confusion, John and I scrambled up the ladder to our spaceship, I climbed in the pilot's seat and started the engine. The spaceship lifted off with a roar and I looked down to wave to the Neanderthals beneath.

Once we’d cleared the spaceport, I turned to John. "So what do you think. Are those people human?"

"They’re more human than some blokes I’ve met down the pub."

I nodded. "Yes, I think we can count them as humans and friends."