He recognised the voice of the redhead with the amazing long hair. ‘Copy, Harry. Is there a problem?’

‘I’m going out back with a ladder to fix my air-conditioner. Just letting you know, so one of your drones doesn’t shoot fifty thousand volts up my rear!’

‘I’ll program a buffer zone around your house,’ the redhead answered. ‘And you be careful – it’s windy out here.’

The racket from the air-con meant Harry didn’t hear the howling wind until it almost snatched the back door out of his hand. Harry isolated the air-conditioner with a switch at ground level, then rested the little ladder against the house and fixed on his leather tool belt and the elastic strap of a head-mounted lamp.

There were a bunch of weird-looking shell beetles crawling on the ground and Harry sprayed the area around the ladder with insecticide before climbing up. The storm was chucking up dust and he considered going down for a set of goggles as he loosened three screws on a safety grille and let it pivot down round the fourth.

He gave the fan blades a wiggle, confirming it was vibration from the cracked bearing making the blades rattle. But when he felt in his tool belt he realised he’d climbed up without the wrench he needed to tighten them.

‘Dammit.’

Harry coughed into his virus mask as he went down the ladder and opened the expanding tool box. He found the wrench in the second layer of drawers, and was about to climb back up when he noticed moving white light.

Nerves kicked in as he looked round the side of the house and saw two panel vans at the gate. Harry charged into the house and roared up the stairs.

‘Charlie, wake the hell up!’

She sprang up sleepily, accidentally leaning on Patrick’s arm and making him yelp.

‘I think the zombies are back,’ Harry shouted as he reached the bedroom doorway. ‘I’ll grab my gun and go wake Vern. You get the boys down in the shelter.’

He reached for the assault rifle on top of his wardrobe, stuck two spare clips in his tool belt, then grabbed the walkie-talkie.

‘What’s going on at the front gate?’ Harry shouted into the box. ‘Front gate, do you copy?’

The redhead spoke. ‘One of my colleagues isn’t well. His replacement is arriving. No cause for alarm.’

But her tone was off somehow, and one sick guard didn’t explain two vans. Back downstairs, Harry stepped out of the front door where he could see the front gate being opened by two men.

When the walkie-talkies got handed out, the guard explained two buttons. One sent an emergency alarm to all the other radios on the circuit, while the other alerted the local police. Harry flipped a protective cover and pressed both buttons as Charlie yelled inside the house.