It wasn’t a normal supermarket trolley, either. It looked bigger, the wires looked thicker. And it hurt like mad when Mrs Tachyon pushed it into the small of your back, which she did quite a lot. It wasn’t that she did it out of nastiness – well, it probably wasn’t – but other people just didn’t exist on Planet Tachyon.

Fortunately, one wheel squeaked. And if you didn’t get accustomed to moving away quickly when you heard the squee … squee … squee coming, the monologue was another warning.

Mrs Tachyon talked all the time. You could never be quite certain who she was talking to.

‘… I sez, that’s what you sez, is it? That’s what you think. An’ I could get both hands in yer mouth and still wind wool, I sez. Oh, yes. Tell Sid! Yer so skinny yer can close one eye and yer’d look like a needle, I sez. Oh, yes. They done me out of it! Tell that to the boys in khaki! That’s a pelter or I don’t know what is!’

But quite often it was just a mumble, with occasional triumphant shouts of ‘I told ’em!’ and ‘That’s what you think!’

The trolley with its squeaky wheel could turn up behind you at any hour of the day or night. No one knew when to expect it. Nor did anyone know what was in all those bags. Mrs Tachyon tended to rummage a lot, in bins and things. So no one wanted to find out.

Sometimes she’d disappear for weeks on end. No one knew where she went. Then, just when everyone was beginning to relax, there’d be the squee … squee … squee behind them and the stabbing pain in the small of the back.

Mrs Tachyon picked things out of the gutter. That was probably how she’d acquired Guilty, with his fur like carpet underlay, broken teeth, and boomerang-shaped backbone. When Guilty walked, which wasn’t often since he preferred to ride in the trolley, he tended to go around in circles. When he ran, usually because he was trying to fight something, the fact that he only had one and a half legs in front meant that sooner or later his back legs would overtake him, and by then he was always in such a rage that he’d bite his own tail.

Even DSS, the rabid dog owned by Syd the Crusty, which once ate a police Alsatian, would run away at the sight of Guilty spinning towards him, frantically biting himself.

The ambulance drove off, blue light flashing.

Guilty watched Johnny from the trolley, going cross-eyed with hatred.

‘The ambulance man said she looked as if she’d been hit by something,’ said Wobbler, who was also watching the cat. It was never a good idea to take your eye off Guilty.

‘What’re we going to do with all this stuff?’ said Johnny.

‘Yeah, can’t leave it,’ said Bigmac. ‘That’d be littering.’

‘But it’s her stuff,’ said Johnny.

‘Don’t look at me,’ said Bigmac. ‘Some of those bags squelch.’