This sudden new surge of hatred was easing the fat boy's pain. He remembered his recent clash with BJ. Dirty shoes and a crumpled tie at the Saint's Day service the other day had earned him a session of detention. Not just ordinary detention like others got, though. Oh, no. BJ knew that that would be no real punishment for him. He'd taken him down to the gym and put him through the lot; the vaulting horse, the horizontal bar, the climbing ropes, ending up with twenty minutes' physical jerks whilst the head boy sat on his arse and smirked.

Ursin-Davies had thought that he might have suffered a heart-attack after that lot. He had coughed and wheezed all night, and then he'd been selected to represent his house on a cross-country run the next day. They knew he couldn't bloody well run. It was all BJ's doing. He had engineered it. The bastard had been waiting at the finishing-point when Ursin had staggered in, a full twenty minutes after everybody else.

'I'll make an athlete of you if it kills you.' the head boy had announced in a loud voice, and all the spectators had broken into peals of laughter. You were expected to laugh like hell at any of BJ's sick jokes. 'Better a dead athlete than a fat scholar.'

'If it kills you'. Ursin-Davies winced at the memory of that jibe, and felt the cold steel of the knife in his sweaty palm.

'I say, Bryce-Janson,' a thirteen-year-old boy called out, shaking a younger colleague in the next bed, 'I think ... I can't make Burlington hear. He's gone all stiff like . . . like he's got polio or something.'

Bryce-Janson sat up hurriedly. He grunted, but somehow managed to slide off the bed and pad across to the boy who had attracted his attention.

'Let me see.' He pulled the other aside. 'Hey, Burlington. Listen to me.' He shook the inert form roughly. 'This is Bryce-Janson. Answer me! D'you hear me? If you're fooling, I'll report you to the Head.'

Ursin-Davies eased himself up on one elbow with difficulty. The nine-year-old was wailing, and those clustered around the silent boy's bed were beginning to panic. Bryce-Janson was trying to cover up his own fear by using his authority.

The bitterness which had been building up inside Ursin-Davies came to the boil. He gripped the handle of the knife. The back of his most hated, enemy was towards him, and he wondered why he hadn't thought of this before. It was all too easy, and no more than the bastard deserved.

A cauldron of hatred seethed inside Ursin-Davies. He forced his knife-arm back and upwards. The muscles were stiff and unyielding at first, but sheer determination defeated the semi-paralytic tendons. It just needed one supreme effort.

He brought the knife down with every ounce of his thirteen stone behind it. It took the head boy between the shoulders, the blade buckling but sinking in up to the hilt with the weight of the blow, twisting and tearing as blood gushed out of the jagged wound.

Bryce-Janson screamed, a strangled, unnatural sound that died away in a hiss of spittle. He sank to his knees, clutching at the sheets and pulling them to the floor with him. Boys stared in horror, disbelief on their faces. Ursin wrenched the knife free and held it up, blood dripping on to the floor. He tried to laugh, but no sound came. Just a baring of the teeth, lips drawn back, spittle frothing, bubbling, bursting. Then came brief realisation, momentary sanity amidst the madness, as his mouth opened with shock.

He gripped the knife again, exerting unwilling muscles, struggling to turn the bloody blade so that it pointed inwards, forcing it up towards his own jowls. Staccato movements, an inch at a time, beads of sweat rolling down his face with the strain.

'No ... no ... Fatty, no!' nine-year-old Montgomery screamed, the only one to realise the full implication of Ursin-Davies's actions.

This time the blade's entry was achieved more easily. It slid into the soft fat without the hindrance of bone, once again going hi up to the hilt, severing the jugular vein, until blood spouted like an oil-geyser, jetting on to beds and boys alike.

The door opened, and Matron entered, a short, middle-aged doctor at her heels.

'These are the boys, doctor,' she was saying, 4it really is most puzzling... and... '

She broke off, saw the tottering boy, the knife embedded in his throat, the fountain of blood, and fell forward unconscious.

The sun beat down relentlessly on the squat buildings which comprised the Biological Research Centre on Can-nock Chase, so that as early as ten o'clock in the morning the heat in Haynes's office was stifling. The air-conditioning laboured under the strain, and the four people in the room knew that by midday it would be virtually ineffective. They all recalled the freak summer of 1976, but this one threatened to break all records. Farmers were forecasting disastrous potato crops again. Fire-brigades were at full stretch in an attempt to combat heath and forestry fires. Yet, suddenly, all these had become of minor importance.

Copies of every daily newspaper for the past week lay spread out on the desk. The headlines bore a similarity as the Fleet Street prophets of doom revelled in the latest sensations. 'BATS FROM HELL SPREAD KILLER DISEASE', 'SCHOOL QUARANTINE AS PLAGUE AND MADNESS STRIKE', 'DEATH VIRUS ESCAPES FROM RESEARCH CENTRE', and so on. The accounts varied. Some followed the truth religiously, others exaggerated. The man in the street would believe that which he chose to believe. In all, fear would predominate.

Haynes regarded Brian Newman, Professor Rickers and Susan Wylie steadily. He fidgeted with his spectacles, and chewed his lower lip.

'It seems you were right, Brian.' He averted his eyes as he spoke. He wasn't accustomed to making apologies, nor to admitting that he was wrong. 'I owe you an apology.'

'Thanks.' Newman said. He could have made it tougher for his chief, but he had no wish to do so. The situation now was far too serious for either of them to indulge in petty jealousies.

Rickers shuffled his feet and mumbled. 'I still can't believe it. It's just not scientifically possible.'

'Well, it's happened, and that's that.' Haynes spoke sharply. 'And right now we've got to do something about putting it right. How have your tests gone, Brian? Is an antidote possible?'

'Not at the moment.' Newman shook his head gravely. 'I injected a fresh lot of bats, but they died in just the same way. I tried taking germs from those which appeared to be immune and injecting the virus into the sufferers. They died. It had no effect.'

'Hell!' Haynes lit a cigarette and blew a cloud of smoke into the air. 'The Press are really gunning for us now. So are our own boys in London. We're the villains of the piece.'

'I am,' Professor Newman corrected him. 'It was my fault that the bats escaped, I was careless enough to knock the cage over.' He noticed Susan blush and start to say something, but his frown silenced her. 'It's got to come out, anyway, and I'm prepared to take full responsibility.' 'Let's get a few facts together first,' Haynes said, 'working from the information we already have. By now a large percentage—it's impossible to quote figures—of bats are carrying the virus. Those which they come into contact with either catch it, and die within a very short time, or else they become carriers themselves. Hence the disease will spread at an alarming rate. It is reasonable to assume, in the light of recent information, that the bats were responsible for the death of the Williams' family and that they caused the horses to bolt on to the road. Therefore the Wooden Stables were their first home after their escape. Then they vanished. Was it because they were disturbed? Let us assume so. Then for some time they disappeared altogether, presumably to some quiet place. The main .bunch, anyway. They chose the upper regions of Lichfield Cathedral's main spire. They were disturbed again, this time by a firm of contractors working on the spire. They came into contact with schoolboys and a headmaster. The headmaster and six boys died horribly from this meningitis type disease within three days. But nobody else. Consequently we can assume, at this point, that humans do not carry the disease. They only catch it directly from the bats. Therefore, the bats are the real menace. If you keep out of their way you're safe, unless of course you meet up with someone in the 'mad' stage of the disease. Williams killed his wife, and that schoolboy murdered the head boy. But can the virus be carried by animals or birds, rats, mice, starlings, all the scavengers, for instance?'