'Yeah well,' said the Doctor. 'Experimental drives don't act like you expect them to. That's why they're experimental.'

'Thank you, Doctor,' said the captain. 'My main concern is what we do to free ourselves from the sandbank.'

'Ah well,' said the Doctor. 'Strictly speaking, you don't.'

Captain Georgina was about to ask him why not when there was a crash from the wall of cold scrambled egg. Three rough-looking, space-suited, helmeted figures charged through the eggy material and came clattering onto the bridge. Their spacesuits were battered and battle-worn, with a skull and crossbones daubed on each of their chests. It took a moment for Martha to recognise the three badger pirates, because they'd put on their helmets.

'Doctor!' said Dashiel, his voice echoing because of the helmet. 'Fort you must 'ave died!'

'Sorry to disappoint you,' said the Doctor. 'How long have you been waiting for us?'

'Er,' said Dashiel. 'Dunno. Coupla days.'

'Sorry,' said the Doctor. 'Got chatting.'

'Who are these people?' asked Captain Georgina, maintaining an impressive air of calm. No, thought Martha, the captain was sneering at the intruders, like they weren't good enough to be in the same room. Around her, Martha saw, the other humans had raised their own elegant, little guns.

'Well,' said the Doctor. 'They used to be pirates, but we've been having words. That's Dashiel, Jocelyn and Archibald.'

'Allo,' said Archibald, waving a hairy paw.

'I see,' said Captain Georgina. 'They do seem to be carrying guns.'

'Oh yeah,' said the Doctor. 'But don't worry about that. I disarmed them hours ago—'

As he spoke, Thomas erupted in a plume of brilliant pink light. He had barely enough time to scream before he had been entirely consumed.

'Ah,' said the Doctor, scratching at his jaw. 'That really shouldn't have happened.'

'They started workin' again,' Dashiel explained, as he shot the brunette who still worked at the horseshoe of computers.

'Oh yeah,' said the Doctor. 'I should have thought of that. The loop affects the guns as well.'

'Fire at will!' cried Captain Georgina. 'Repel the invaders!'

'Wait!' cried the Doctor. 'Wait!'

One of the uniformed men dived forward, firing his elegant little gun into the attacking badgers. A blast of bright white energy smashed into Dashiel, hurling him back into the wall of scrambled egg. His broken body lay steaming on the ground.

'Huh,' said Archibald as he fired back at the uniformed man. The man was consumed in pink light. Archibald and Jocelyn ran forward, using the horseshoe of computers as cover while they fought the rallying humans.

'Oh, this is just silly!' said the Doctor. He grabbed Martha's hand and they rushed to the only other shelter – the transmat booth set into the wall. The door opened easily, and the Doctor locked it after them with his sonic screwdriver.

'You've got to stop them!' said Martha.

The Doctor was watching the fire fight closely. Captain Georgina and her men were caught with nowhere to hide. They fought back valiantly, but it was easy for Archibald and Jocelyn to pick them off one by one. Martha felt a little dizzy, her eyes blinded by so much brilliant pink and white light.

Yet the Doctor seemed to find it all fascinating. 'How did they get through the wall?' he asked, as if watching some scientific experiment and not a room of people being killed.

'Doctor, they're wiping each other out!' said Martha.

'Oh yeah,' said the Doctor easily. 'They're bound to. But then they'll just wake up again.' He turned to look at her, then seemed more taken by the controls of the transmat. 'That's funny,' he said.

'Oh, it's hilarious,' muttered Martha as she watched another couple of uniformed men eaten up by pink light. There was just Captain Georgina and one of her men left, curled up close to the far side of the horseshoe of computers, just out of sight of the badgers.

'Thomas was right,' said the Doctor, still scrutinising the transmat controls. 'This hasn't been used in hours. You couldn't use it anyway. The delay between the two booths would just tear you apart. No way out, I'm afraid.'

'Doctor!' said Martha through gritted teeth, as Archibald reached round the horseshoe to shoot the man beside Captain Georgina.

'Well, that is funny,' said the Doctor. 'Because when we were down in the engine rooms, something was trying to get through. Which means, since Thomas went and came back again already, that whoever we saw arriving hasn't set off from here yet.' He seemed to notice Martha wasn't paying him any attention, and looked back at the fighting.

Jocelyn and Archibald were creeping round the sides of the horseshoe of computers, while Captain Georgina, alone now, waited for them to reach her. She cradled the elegant little gun in her hands. After a moment Martha realised she wasn't just cradling it, she was working controls in the handle.

'Gotcha!' said Archibald, leaping out at her and firing. From the far side of the computers, Jocelyn was leaping too, keen not to miss out on the kill.

But before the pink energy hit Captain Georgina she exploded in white light. The blast tore through the horseshoe of computers, screens and keyboards shattering all around. Jocelyn disappeared behind the explosions. Archibald's body was sent tumbling across the room, so that he smashed into the door of the transmat booth and lay still. Martha reached for the handle of the door, but it wouldn't open.

'I have to help him,' she said quietly.

'You can in a minute,' said the Doctor, busy again with the controls of the transmat.

'They've killed each other,' said Martha so quietly she barely heard herself.

The Doctor turned to her, put a hand on her shoulder. 'Yes,' he said. 'But they'll be fine again in a minute.'

'But they'll just get up and start fighting again,' she said. 'It's so stupid!'

'I know,' said the Doctor gently, his eyes looking deeply into hers. And then he grinned. 'Which is why we'll have to be really clever if we're going stop them.'

'Oh,' she said. 'You've got a plan.'

'Yes,' he said. 'And, even if I say so myself, it's really quite a good one.'

TEN

The Doctor pointed the sonic screwdriver at the door of the transmat booth, and with a click the door unlocked. The moment it opened, Martha was assaulted by an appalling stink of death and burnt fabric. She stepped carefully over Archibald's smoking body, following the Doctor over to the smashed and still burning horseshoe of computers.

She glanced back and Archibald's body had vanished. Martha knew he'd be coming back, that all the humans and badgers would be resurrected. And yet it didn't make her feel any less sick at having watched them slaughter one other. She felt again the cold steel blade that had killed her earlier that day. The time loop on the Brilliant brought them back from the dead, but it didn't stop violence and pain.

The Doctor fussed with the horseshoe of computers, the keyboards and screens all suddenly just as they had been before the badgers attacked. Then, happy with whatever he'd done, he collected up the scattered guns and weapons and set to work on them with the sonic screwdriver. He had that serious, single-minded look in his eyes he often got when tinkering.

'Anything I can do?' she asked.

'Um,' he said, glancing quickly round. 'Don't think so. But it's nice of you to ask.'

She stuck her hands in the pockets of her jeans and walked slowly round the horseshoe of computers. For all she was bored, she had the eerie feeling of all sorts of activity going on wherever she wasn't quite looking. There were bodies and wreckage strewn across the floor, but she'd glance away and then it would be tidy. It was just easier to close her eyes and count slowly up to ten.