He checked once more to make sure that there was nobody about, and then he lifted the can of paraffin out of the back. Just two gallons, but it would be more than enough.

The shrubs should have been flowering by this time of year, a mass of sweet smelling red and pink. Instead they had a look of dereliction about them. Somehow the greenery had survived in spite of the clinging starling droppings. There had been no rain to wash the excreta away.

Tyler wrinkled his nose. The sour aroma was stronger than the smell of woodsmoke. He coughed. Maybe if the bushes blazed for a week it might get rid of the stench and scorch up the layer of droppings. It was the only way.

Usually there were starlings in evidence, one or two flying about, maybe nesting, or just too lazy to go out to feed on the surrounding fields. They chirped noisily. This morning, however, there was not a bird to be seen. Not a cheep. Silence. Sheer desolation.

Ken Tyler noticed this as he walked towards the rhododendrons, carrying his can of paraffin. Where had all the birds gone? Still, whenever they'd gone, when they came back to roost that evening they'd be in for a nasty shock. They'd singe their wings if they came too close. The starling problem was as good as solved.

As he approached the bushes the stench was almost overpowering, a' combination of excreta and rotting flesh. Many starlings died from natural causes out of the thousands clustering in the bushes, and none of the scavengers of the countryside were prepared to clear up the corpses.

'Soon settle that,' Ken Tyler said as he unscrewed the cap on his jerry-can and began splashing the contents over the nearest rhododendrons. 'Cremate the bastards!'

He stood back, struck a match, and flung it at the paraffin-soaked bushes. It fell to the ground, lay burning for a couple of seconds, and then with a roar a small sheet of flame shot up, spreading even before it reached the topmost branches.

Tyler felt the scorching heat on his back as he ran for the Land-Rover. Those excreta-covered bushes were tinder-dry. The blaze was spreading far quicker than he had thought it would.

As he opened the door of the vehicle he noticed a movement out of the corner of his eye, and turned back towards the fire. Tongues of flame crackled on dead branches, leaping into the air hungrily as black smoke billowed up in a huge pillar, burnt leaves floating in the air and carrying the sparks. But that was not all.

Whirling upwards, at first indistinguishable from the sparks and smuts but then recognisable by their very numbers and speed, were hundreds of pairs of tiny wings, crazily veering in all directions. In a panic, soaring and diving, their one aim was to escape the heat of the furnace.

Tyler's first thought was that these living creatures were starlings now being forced to relinquish their stronghold. Yet as he climbed into the driving seat, slammed the door and gunned the Land-Rover's engine, the truth suddenly dawned on him.

'Christ alive!' he muttered, glancing back. 'Bats!' The radio broadcast came back to him. 'Report any sightings of bats immediately.'

The Land-Rover bumped and jerked at 40 m.p.h. down the uneven track, its driver heedless of potholes or overhanging branches. His first thought was to return to his cottage and telephone the information to the Research Centre up on Pye Green.

Then he realised that he could not do so without incriminating himself. On no account must he admit to being up here on Castle Ring at the time when the fire broke out. No way. To hell with the bats. That was where they had come from, according to a sensationalist newspaper, and for all Ken Tyler cared that was where they could return. He drove back into the yard adjoining his small cottage close to Castle Ring. The bedroom curtains were drawn. His wife still slept. She would not be aware that he had even been outside the yard. Nobody else had seen him, and he had passed no vehicles.

As he went inside the telephone was ringing. It was the Fire Officer, advising him that part of the Castle Ring Estate was on fire. They could only spare a skeleton force.

There was no chance of saving the large expanse of rhododendrons.

Throughout the county of Staffordshire firemen and volunteers fought blazes. Brownhills Common was ablaze, and the A5 traffic had been halted. A verge smouldered at Hilton, near Lichfield, and a couple of soldiers from Whittington Barracks watched over it, stamping out the flames which broke out periodically. A more serious fire was threatening to destroy Sutton Park, where the combined fire-fighting forces of Staffordshire and Warwickshire were losing their battle.

All of these men saw the bats passing over, flitting through the drifting smoke, but it was well into the day before the reports reached the Biological Research Centre on Cannock Chase.

Professor Brian Newman's bungalow was situated on the outskirts of Cannock. Small and compact, there was nothing to distinguish it from the other houses in the small cul-de-sac. Yet its photograph had already appeared in at least one daily newspaper, the caption beneath it stating that 'this is the residence of Professor Newman, who developed the killer virus and allowed it to escape into the world'.

Newman glanced through the local evening paper which he had picked up on his way back from the Centre less than an hour ago. His name was featured again in the bold front-page headlines. He grimaced, and tossed it to one side.

'Well, they've really singled me out for the blame now,' he said, with bitterness in his voice. 'They have to have a scapegoat, though.'

'Then they're damned fools,' Susan Wylie replied hotly. 'They seem to overlook the fact the you're the one person who stands any chance of wiping out these bats.'

'I wish I could share your optimism.' Newman smiled wanly. 'Weeks of tests in an attempt to find an antidote for the virus, and still nothing to show for my efforts.'

'It'll come.' Susan assured him. She moved across to where he was sitting, and slipped an arm around his neck. 'It's got to. There has to be an antitoxin somewhere.'

'It's the latest reports that worry me,' Newman said, squeezing her hand gently. 'Large numbers of bats have been reported heading south-west, sighted at Brownhills, Lichfield and Sutton Park. Now what the hell's going on? A migration of some sort? And what caused 'em to move? There are no reports beyond Sutton Park, but my guess is that they won't settle there. The whole bloody area is ablaze. If they continue on their present course then our worst fears are confirmed.' The cities?'

'Yes.' He nodded. 'Birmingham, at a guess. Then the panic will really start. There've been no deaths lately simply because the bats have been hiding out in remote places away from populated areas. Imagine what could happen. Thousands of derelict slum dwellings for them to hide and breed in. A dense population. The hospitals would never be able to cope. There would be widespread chaos, maybe even a breakdown of law and order. A spread of anarchy.'

'You're a pessimist,' She kissed him on the forehead. 'Well, I'm an optimist. Maybe the whole thing's over, and the virus is dead. The bats might never be heard of again.'

Her attempts to raise his spirits were interrupted by a crashing and splintering of glass. A heavy object thudded on to the carpet and bounced against the fireplace. It was a jagged half-brick. The curtains blew inwards as the warm breeze of a hot summer's night wafted through the smashed pane.

'What the hell!' Professor Newman was on his feet immediately. A hail of stones crashed into the small living-room, smashing the remaining panes of glass in the window, their force retarded by the obstructing flapping curtains.

'Come on out, Newman!' came a shout from outside. 'Show yourself, you bastard!' Someone was hammering and kicking on the front door. 'What's going on?' Susan breathed. Newman pushed her behind him and moved to the window, parting one of the curtains slightly so that he could see outside. The scene which met his eyes caused him to catch his breath.