He nodded grimly. ‘Dr Potter’s the one who imprisoned me down here. The two goons are paid heavies. They just do as they’re told.’
‘But…’ Mrs Pargeter looked up in bewilderment.
The doctor, very coolly and efficiently, explained it to her. ‘Yes. A lot of people just do as they’re told. It’s wonderful what most people can be persuaded to do when you’ve got a bit of dirt on them.’
Mrs Pargeter, whose investigative methods had frequently borne out the truth of this statement, nodded.
‘And I have a lot of dirt on a lot of people,’ Dr Potter continued. ‘A surprising amount of dirt. I had enough on Mr Arkwright when I returned from Hong Kong to ensure that he would give me the job here, and allow me all of Brotherton Hall’s resources for my work. I had enough on Stan and’ — he gestured contemptuously towards the ambulance men — ‘ these two to command their unquestioning obedience. And, if I chose to use it, I’d have enough to get Truffler Mason put away for a very long time.’
‘You haven’t got anything on me,’ said Mrs Pargeter defiantly.
‘No, but then I don’t need anything on you. You’re just a nuisance, a minor irritation. There’s nothing you can do to help me in my work.’
‘And what is that work?’
The thin face crackled into a thin smile and the mud-coloured eyes produced what in any other eyes would have been a twinkle. ‘I am a research scientist, Mrs Pargeter. Rather a good one, as it happens. The trouble is, the kind of research I do might not be sanctioned in a traditional pharmaceutical company. Such institutions tend to be very old-fashioned — though I can guarantee that, once my current product has reached its final form, all the drug companies will instantly copy it.’
‘What is the product?’
‘Ah, Mrs Pargeter, ever ready with the direct question. My product is something on which I have been working for many years. I first developed it for… well, I don’t think that’s really relevant at the moment. Suffice it to say that the product is very nearly in its final form. And when it has reached that form, it will make me a very rich man indeed.’
‘It’s for slimming, isn’t it? To change a body’s basic metabolism, to turn a naturally fat person into an unnaturally thin person?’
He nodded acknowledgement of her investigative expertise. ‘Very good, Mrs Pargeter. That is exactly what it is.’
‘And when you get it right, you’re going to market it through Sue Fisher’s Mind Over Fatty Matter outlets.’
‘I am indeed. When you have the best product in the world, you go for the best distribution system. Sue Fisher is very excited about the drug.’
‘Even though it has been tested on student guinea pigs and caused the death of at least one of them?’
Dr Potter shrugged. ‘The advances of science have never been achieved without casualties, Mrs Pargeter.’
Suddenly in her head were the words she had overheard on her first night at Brotherton Hall. ‘But there’s nothing you can do about it. They’re going to kill me, and nobody can stop them.’
The girl had not been talking about people going to kill her — not directly at least. She had been talking about the drugs she had been paid to take, drugs whose deleterious effects were by then too far advanced to be halted.
Mrs Pargeter looked contemptuously at Dr Potter. ‘You just don’t care, do you? You don’t care about the girl who died.’
He shrugged again. ‘She took a risk. She knew she was taking a risk. And she was extremely well paid for the risk she took.’
‘But what about her parents?’
‘She said she had no parents. I was extremely careful only to take on applicants who had no close family.’
‘So that if anything went wrong, no one would come looking for them?’
‘Exactly.’
‘The girl did have parents.’
‘If she lied to me, that’s hardly my concern. Come on, she was being well paid for her trouble. How many students get to earn five thousand pounds for four weeks’ work?’
‘That five thousand pounds is a fat lot of good to her now.’
Dr Potter’s face distorted into another smile as he said, ‘I apologize for having to correct you, Mrs Pargeter, but might I suggest that “a thin lot of good” is a more appropriate expression?’
He laughed drily, demonstrating the huge gulf between his sensibilities and those of normal human beings.
‘How much did anyone else know of what you were doing, Dr Potter?’
‘Very little. Mr Arkwright didn’t want to know any details. He thought they might distress him… which indeed they might well have done. He just did what I asked of him without asking any questions.’
‘Yes,’ Ank agreed bitterly, ‘and I feel pretty dreadful about the whole business now that-’
‘Be quiet!’ If Dr Potter had been looking for a demonstration of his power over Ankle-Deep Arkwright, nothing could have been more effective than the way those two little words brought instant silence. ‘Of course, there were drawbacks to his complete ignorance. If Mr Arkwright had known more about my experiments, he wouldn’t have investigated the dead girl’s room and so inconveniently supplied you with the name of a real person, Mrs Pargeter.
‘Still, couldn’t be helped. Generally speaking — until the last few days when I’ve been forced to keep him out of the way down here, Mr Arkwright has been very biddable. As I said, remarkable how ready people are to do as you wish, when you know enough about their criminal background. Though, as you pointed out, Mrs Pargeter… I don’t have any dirt on you.’
‘No.’
‘So…’ he continued, his voice growing ever silkier with menace, ‘I can’t be confident of buying your silence with my own, can I?’
‘No,’ she replied defiantly.
‘Which means I may have to effect your silence by some other method…’ Muddy eyes gazed thoughtfully at her.
The ambulance man with the gun volunteered, ‘Blow her away, shall I?’
Dr Potter winced at this crudeness. ‘No, for heaven’s sake. I don’t want to have to dispose of a body with bullet-holes in it. No, I think some kind of “accident” may be more appropriate…’
‘Like the one you arranged for Lindy Galton?’ suggested Mrs Pargeter, determined to keep him talking for as long as possible.
‘Dear me, no,’ he replied fastidiously. ‘I don’t like repeating myself. Anyway, even the notoriously dim British police force might get suspicious if a second corpse were to succumb to the embrace of the Dead Sea Mud. But I think it should be an “accident”, none the less…’
He mused for a moment, then looked at her with glee as a thought struck him. ‘Of course, you are somewhat overweight, aren’t you, Mrs Pargeter…?’
‘It’s never worried me.’
‘No, but no one’s to know that. No one like a coroner, say. You wouldn’t be the first’ — he chose his word carefully — ‘ mature woman to have died from over-exercising.’
‘I don’t take any exercise. I never have. You can’t make me exercise.’
‘Oh, but the beauty of the situation is that I can, Mrs Pargeter. I can.’
‘But why should I be found in Brotherton Hall, anyway? I’m not booked in here or-’
‘Mr Arkwright is extremely proficient at falsifying registration records,’ oozed Dr Potter, ‘as I believe you’ve already discovered.’
This was too much for Ank. ‘No! I’m not going to be party to anything that hurts Mrs Pargeter! All right, I’ve done some stuff for you I wish I hadn’t, but-’
He got no further. At a signal from Dr Potter, the ambulance man with the baseball bat swung it upwards to connect with the point of Ankle-Deep Arkwright’s jaw. His body sprawled backwards to slump against the wall.
Stan the Stapler made a move forward, but he was caught in the hollow at the back of his neck by the butt of the other ambulance man’s automatic. He too crumpled to the ground.
‘You stay with them,’ the doctor curtly ordered the one with the gun. ‘You bring her,’ he told the other.
Stowing his baseball bat under one arm, the ambulance man locked the other round Mrs Pargeter. She tried to struggle, but could do nothing against his superior strength.