Free Johnny and the Bomb by Terry Pratchett

heavy, although the piles of bags did weigh it down. But it did need a lot of steering. Even with all of them helping – or, Johnny thought later, perhaps because of all of them helping – it skidded and wobbled as they tried to keep it in a straight line.
    â€˜If we can get out of the other doors, we’re in the High Street,’ said Johnny. ‘And it can’t go in there because there’s bollards and things.’
    â€˜I wish I had my five-megawatt laser cannon,’said Bigmac, as they fought the trolley round a corner.
    â€˜You haven’t got a laser cannon,’ said Yo-less.
    â€˜I know, that’s why I wish I had one.’
    â€˜Ow!’
    Wobbler leapt back.
    â€˜It bit me!’ he screamed.
    Guilty stuck his head out of the heap of bags and hissed at Johnny.
    Security guards were strolling towards them. There were five kids arguing around a trolley, Bigmac was among them and, as Yo-less would have pointed out, one of them was black. This sort of thing attracts attention.
    â€˜This trolley might be a time machine,’ said Johnny. ‘And that car … Kirsty thinks someone’s after it. I mean me. I mean us.’
    â€˜Great, how do we make it work?’ said Bigmac.
    â€˜A time machine,’ said Yo-less. ‘Ah. Yes?’
    â€˜Where’s this invisible car got to?’ said Wobbler.
    â€˜We can’t go out of the other doors,’ said Kirsty, flatly. ‘There’s a couple of guards there.’
    Johnny stared at the black dustbin liners. Then he picked one up and undid the string. For a moment his fingers felt cold and the air was full of faint whispers—
    The mall vanished.
    It vanished above them, and around them.
    And below them.
    They landed in a heap on the grass, about a metre below where they’d been standing. The trolley landed on top of them, one wheel slamming into the small of Johnny’s back. Bags bounced out, and Guilty took the opportunity to scratch Bigmac’s ear.
    And then there was silence, except for Bigmac swearing.
    Johnny opened his eyes. The ground sloped up all around him. There were low bushes at the top.
    â€˜If I asked what happened,’ said Yo-less, from somewhere under Bigmac, ‘what’d you say?’
    â€˜I think we may have travelled in time,’ said Johnny.
    â€˜D’you get an electric feeling?’ said Wobbler, clutching his jaw. ‘Like … all your teeth standing on end?’
    â€˜Which way did we go?’ said Yo-less, still talking in his deliberate voice. ‘Are we talking dinosaurs, or mutant robots? I want to know this before I open my eyes.’
    Kirsty groaned.
    â€˜Oh dear, it’s going to be that kind of adventure after all,’ she hissed, sitting up. ‘It’s just the sort of thing I didn’t want to happen. Me, and four token boys. Oh, dear. Oh, dear. It’s only a mercy wehaven’t got a dog.’ She sat up and brushed some grass off her coat. ‘Anyone got the least idea of where we are?’
    â€˜Ah,’ said Yo-less. ‘I see there’s grass. That means no dinosaurs. I saw that in a film. Grass didn’t evolve until after there were dinosaurs.’
    Johnny stood up. His head was aching. He walked to the edge of the little hollow they’d landed in, and looked out.
    â€˜Really. Someone’s been paying attention,’ said Kirsty. ‘Well, that narrows it down to some time in the last sixty million years.’
    â€˜ Proper time travellers have proper digital readouts,’ Wobbler grumbled. ‘No grass? What did dinosaurs eat, then?’
    â€˜You only get digital time machine clocks in America,’ said Bigmac. ‘I saw a film about a time machine in Victorian England and it just had light bulbs. They ate other dinosaurs, didn’t they?’
    â€˜You’re not allowed to call them dinosaurs any more,’ said Yo-less. ‘It’s speciesist. You have to