Thin Air

by Gerald Hammond

  ‘You knew in advance that I would tell you to break the law,’ Ian said.

  ‘Of course. This was made for Number Two Bore, equivalent to two-two.’

  Keith dropped an airgun pellet through the loading hole and took up a small gadget from the table. ‘It requires the use of a cocking key,’ he explained. As he turned the key there was a sharp click and a stud popped up at about the mid-point. He raised the stick, sighted along it and fired by pressing the stud with his left thumb.

  Ian had the binoculars up again. ‘You’re off to the right,’ he said.

  ‘That’s usual with a stud trigger. This time I’m in no doubt whatever that the slug would have gone through several thicknesses of board.’ Repeating the same steps, he fired another four slugs into the target board. The sound was sharper but lighter than that of the conventional rifle.

  ‘Not such a good group,’ Ian said.

  ‘Well, it wouldn’t be. The cranked sticks are more accurate because you can shoot from the shoulder, but the shape must have been a giveaway for a poacher. If you think that you can do better, have a go.’

  ‘Thank you,’ Ian said, ‘but no. If you’re trying to convince me that an air cane could have been used to kill Old Murdo—’

  ‘Could,’ Keith said. ‘Not that it did.’

  ‘Oh. Anyway, you’ve succeeded,’ Ian finished doggedly. I suppressed a sigh as my favourite theory vanished into thin air.

  ‘And our next little item,’ Keith said. He picked up a gun that resembled the flintlock fowling pieces that figured largely in his collection, but with a metal sphere slightly larger than a tennis ball fitted in front of the trigger guard. ‘I’d have liked to fire this one for you, but I won’t. Seventeenth century, maker unknown. The ones with a copper air reservoir are comparatively safe – the reservoir fails by splitting if it fails at all – but when an iron ball like this fails it goes off like a grenade.’

  ‘If somebody had been lugging a thing like that around, he’d have been noticed,’ Ian said.

  ‘Very true. And for my next trick . . .’ Keith laid down the antique and picked up an unusually shaped modern gun. ‘A pump-up air rifle by Crossman. I imported it for the keeper at Horsefield Great House and I’ve borrowed it back from him. He likes it for vermin control because it’s comparatively quiet and the ammunition’s cheap. Well above the permitted power, so he holds it on his Firearms Certificate.’

  ‘Now, just a minute,’ Ian said sharply. ‘I looked through our computer records and I didn’t see it.’

  ‘I can’t help that. It’s on his certificate or I wouldn’t have sold it to him. One of your clerks in the Firearms Department probably thought the keeper was being over-meticulous. “Airgun,” he thought to himself and he didn’t bother transferring it to the record.’

  ‘I’ll have his balls for bools,’ Ian said. (Bools, I knew, were boy’s marbles – the word almost certainly coming from the French.) ‘He isn’t paid to think. Go on.’

  ‘Next aiming mark.’ Keith worked a bolt which incorporated a sliding sleeve, loaded a pellet and fired. I thought that the noise was less than that of the air cane. ‘Muzzle velocity about six hundred and fifty feet per second,’ he said. ‘The Sheridan gets up to nearly eight hundred. But that’s against about five-fifty for the ordinary spring-operated boy’s airgun. Not a hell of a difference when you remember that the quicker it’s moving the faster it decelerates.’ He loaded and fired several more shots. ‘There are more powerful gas-operated air weapons, but I don’t know of any in this neck of the woods. I doubt if any of these shots have gone all the way through.’

  Ian peered through the binoculars. ‘They haven’t,’ he said. ‘Beautiful group, though.’

  ‘Thank you. It’s the sudden uncoiling of the spring that throws an ordinary airgun all over the place. Pump-ups don’t have that problem. Back to the two-two rifle.’ Keith made the substitution. ‘Waisted airgun pellet and blank cartridge.’ Keith fired two shots, each time dropping a pellet into the breech and pushing it home with the brass cartridge. ‘Those were with dummy-launcher blanks. Next the “Green”, three-grain cartridge for the humane killer . . . now nail-gun blanks . . . and finally just plain blank cartridges as used in a shotgun adaptor for dog-tests. How’s that?’

  With the naked eye I could see that the middle of the target board seemed to have been attacked by deathwatch beetle. Ian lowered the binoculars. ‘Not a good group,’ he said. ‘Some of them keyholed and I think that only one of them went all the way through.’

  ‘We’ll take a look in a minute,’ Keith said. ‘I’d expect you to be right.’

  ‘But which one of those represents what Old Murdo’s killer really did?’ Ian asked.

  ‘None of them.’

  Ian drew in his breath in an impatient hiss. ‘Then why are we wasting my time and a lot of expensive ammunition – for which no doubt you will expect to be reimbursed—?’

  ‘You sound more like your super every day,’ Keith said. ‘You’re going to have to sell the explanation to your highheidyins, the Procurator Fiscal, the Sheriff and probably a jury, so I wanted you to have an idea of the comparisons. Some prat’s bound to start asking awkward questions to get his name in the papers, and you want to be able to show that you’ve been as thorough as anybody could have been.’

  He put down the rifle and picked up the last weapon. ‘Now to the common or garden, low-powered air rifle. This is Young Murdo’s, recovered from the shop this morning.’ Keith cocked it by levering down the hinged barrel, dropped in a pellet and fired. The lower velocity was evident from the softer sound and the delay before the pellet rapped into the board. Keith loaded and fired four more times in quick succession.

  ‘Now watch,’ he said, reloading. He added a few drops from a Three-in-One oil tin. ‘This oil was in Young Murdo’s bag, which Ronnie picked up.’ When he fired, the slap of the pellet followed too quickly to be distinguished from the loud crack of the shot. I was not ready for it and I jumped.

  Ian raised the binoculars. ‘You’re low,’ he said. ‘But it certainly went clean through. I can see daylight. What in God’s name did you do?’

  ‘Let’s take a look,’ Keith said. He laid down the air rifle with as much care as if he had been handling a Best London shotgun and we walked forward. The oak plank was well riddled with holes. The earlier shots from Young Murdo’s air rifle had penetrated but the skirts of the pellets were still visible. When Keith turned the plank round, the lower shot could be seen to have punched a large splinter out of the reverse side on its exit.

  ‘It’s called “diesel action”,’ Keith said. ‘The ordinary airgun uses thin air, compressed by one mechanical action or another, to propel the pellet. Sometimes an airgun gets over-lubricated with a light oil. And some users put a drop of oil behind the pellet to give it both lubrication and a good seal. If the action is already warm, the oil can vaporize. When the gun’s fired, the compression in the air chamber shoots the temperature straight up to around eight hundred degrees centigrade. That’s quite enough to ignite the oil vapour and produce a considerable rise in pressure.’

  I listened intently to Keith’s words. My memory had at last thrown up an incident in my boyhood and I could see how Keith’s story was going to end.

  Ian studied both sides of the plank in silence. ‘Why did it shoot low?’ he asked at last.

  Keith shrugged. ‘Possibly what’s known as muzzle-flip. More probably, the extra pressure caused the barrel to pivot slightly downward in a beginning of the reloading action.’

  ‘So Old Murdo’s death . . .?’

  ‘Was accidental. Young Murdo was furious with his father. He needed to blow off steam and at the same time he wanted to give the old man a fright. Simon noted how dusty he was. If you still have the clothes he was wearing, you’ll probably find that the dust is clay soil and rape-seed, not the sandy stuff down in the gully. He crawled along between the rape crop and the hedge and fired from the corner, as he thought, over his father’s
head. But he’d given his air rifle, which had been in a hot sun all morning, a little more oil. The result was a very powerful shot, some inches lower than his point of aim. The old man fell but, at the time, Young Murdo probably thought that he’d fainted. He may have thought, or even half hoped, that he’d provoked a heart attack.

  ‘When he realized that he’d shot his father, Young Murdo was scared to say anything. He was horrified. Over the next twenty-four hours it sank in. He knew that he’d killed his father. The old man might have been a cantankerous old cuss threatening his son’s romance, but he was also the sheet-anchor of the family. The poor lad never knew that his father had a brain-tumour that was going to carry him off anyway. On top of all that, the effect of that particular shot would be a mystery to him. It must have seemed like the work of the evil genie haunting him. Something had happened that he couldn’t understand and that he was sure nobody, especially the incredulous Inspector Fellowes, was going to believe.

  ‘I think you’ll find that Sheila McKee had seen something from the knoll. She hadn’t seen it all, but enough to make her wonder. I suggest that you put it to her through Ralph Enterkin; she’ll come clean.

  ‘Sheila McKee broke off with Young Murdo and that proved to be the last straw. He went back to the rabbit-holes, sprinkled some water, followed it up with Cymag, stuck his head inside and took a deep breath.’

  Ian stooped and fingered the exit hole. ‘Accident followed by suicide,’ he said. ‘You’ll give me a precognition covering the technical part of this?’

  ‘As soon as I’ve carried out some more tests. I’d want to be able to quote figures about penetration, just in case the Procurator Fiscal has any doubts.’

  Ian stood, rubbing his neck, for a full minute. ‘I’d better get back,’ he said. ‘I’ll have to call off the other enquiries and report to my chiefs.’ He walked off towards his car and then stopped and looked back. ‘Thanks,’ he said.

  ‘Any time,’ said Keith.

  Ian nodded and walked on.

  ‘You could give me a hand with this table, if you insist,’ Keith said.

  The table was only a light card-table but the weight of the guns turned it into an awkward burden. We carried it to the French windows. Ian was waiting impatiently at the corner of the house, beyond earshot.

  ‘I think you should come over and tell me a little more,’ I said quietly.

  ‘Damned if I do.’

  ‘Yes, you will,’ I said. I took the Three-in-One tin off the table. Keith checked a quick movement of his hand. I dropped the tin into my pocket and caught up with Ian at the car.

  Ian seemed to be preoccupied during the journey, but he roused himself once to sniff the air. ‘What’s that smell?’ he asked.

  ‘I can’t smell anything,’ I said.

  *

  The house, when Ian dropped me at the foot of the steps, was empty except for lonely echoes. Alice had left me something in the microwave oven. I heated it up and ate it before heading for the study. Otherwise, I knew, it would be congealed on the plate the next time I saw it.

  I always think better in front of my word processor, where thoughts can be assembled and pushed around until they make sense. I toyed half-heartedly with my problem. I knew that Keith would come and, sure enough, in mid-afternoon I recognized the sound of his jeep. I had left the doors open and when he reached the threshold I called to him to come in.

  He entered the study with the caution of an animal nosing a trap, ignoring the chair that awaited him. ‘Is Alice at home?’ he asked.

  ‘She’s taken the babes to visit her aunt in Kirkcaldy. That’s why I suggested that we meet here. We have privacy.’

  ‘What did you want to talk about?’

  ‘Sit or stand,’ I said. ‘It’s all the same to me. That was a load of rubbish you sold Ian, wasn’t it?’

  Keith sat down slowly. ‘I don’t know what you mean,’ he said.

  ‘Yes, you do.’ I held up the Three-in-One oil can. Without Ian’s presence he could make a proper grab for it, but I was too quick for him. I dropped it into a desk drawer, out of his reach.

  ‘Give me that,’ he said.

  ‘Certainly not. It’s evidence. Not that it would make any difference if you grabbed it and drank it, except to your insides. Ian noticed the smell in the car. I’d only have to remind him. You faked the whole thing, didn’t you? Do you really think a sheriff’s inquiry will go along with it?’

  ‘I don’t see why not,’ he said defiantly. ‘Accident and suicide. A very satisfactory verdict from everybody’s point of view. Why don’t you like it?’

  I may not know much about guns,’ I said, ‘but I know you better than Ian does and I can usually tell when you’re . . . dissembling, to put it nicely.’

  ‘You bastard,’ he said, more in anger than sorrow. ‘Almost every word I told Ian was the truth. Tell me what you think doesn’t fit.’

  ‘So that you can polish up your version?’ I was beginning to enjoy myself. It is not often that I can argue with Keith successfully. I refreshed my memory with a glance at the monitor. ‘For a start, I had an airgun when I was a boy. I used to lubricate it generously. One day I was shooting at a milk bottle full of water that I’d put on the sundial on the lawn. My shots were just bouncing off it. But my third or fourth shot went off like the crack of doom. The bottle shattered and for a moment there was a rainbow hanging in the air. The rainbow in the spray when Jean Mather was using the power-hose on her car almost reminded me of it, but not quite.’

  ‘There you are,’ Keith said. ‘You’ve proved my point.’

  ‘But it only happened once out of all my shots. You read my notes. I noted down that Young Murdo shot a rabbit at about twenty yards and boasted that he could kill them dead at three times the range. That means that he could produce a powerful shot whenever he wished. But if the pressure kicked the barrel down, he couldn’t possibly connect with a rabbit regularly at long range.’

  ‘He could probably prevent that happening by keeping a good grip on the barrel,’ Keith said, too quickly.

  ‘You think so? But again, I was standing right behind you when you fired that last shot. I thought at the time that you dropped your aim.’

  ‘And is that all?’

  ‘Not by a mile. You skated rather evasively around the question of heat. By the time Young Murdo came to fire at or over his father, it must have been many minutes since his last shot. And he’d been crawling along in the shade of a hedge. His airgun would be barely warm.

  ‘Then there was the disturbance at the corner of the rape-field. From what Ian said, I gathered that it must be about where Young Murdo would have dropped his gear when he ran to join us beside his father’s body. Maybe he was concerned about a cheap airgun or the tin of Cymag, but I don’t think that he was looking for either of those. What’s so special about that oil-tin that doesn’t smell like oil?’ When he hesitated, I added, ‘I’ve got more than enough to write it up already.’

  ‘But you wouldn’t,’ he said. He bit his lip and then made up his mind. ‘All right. Promise me that you won’t say or write any of this while they’re still in the neighbourhood?’

  ‘I promise.’

  He sighed. ‘Sniff it,’ he said.

  ‘I already sniffed. Whatever it is, it isn’t Three-in-One oil,’ I said. ‘The smell took me back, but I can’t place it.’

  ‘Something much more volatile than Three-in-One oil,’ Keith said. ‘I’m fairly sure that it’s model aircraft fuel. With something like that in the works, a spring airgun will diesel almost every time – and with more power than gun-oil would give it. If you want an airgun to diesel on a light lubricating oil like Three-in-One, you usually have to fire it first without a pellet, to get the oil heated and vaporized, and then fire it again with a pellet up the spout. Happy now?’

  ‘I wouldn’t claim to be happy. I don’t like it much. But at least it’s the truth at last. Isn’t it?’

  Keith nodded. ‘Ian fell into the trap and I hope
he stays there. Sometimes I worry for the intelligence of any grandchildren Deborah gives me. A policeman should be seeking the truth, not just a solution.’

  My conclusions were falling into place. ‘So Young Murdo did deliberately shoot his father. The McKee girl, from her haunt on the knoll, saw him go sneaking off in the direction of the farmhouse. She broke off with him, which pushed him over the edge.’

  ‘But,’ Keith said, ‘when Ian goes to question her again and suggests an accident, she’ll speak up. She may have been horrified by what she suspected, but he was still her first love. My guess is that she’s been holding her tongue rather than accuse the dead boy of murder as well as suicide.’

  ‘Which is pretty much what we’re doing,’ I pointed out.

  ‘So it is. The thing is, Bertha Heminson may be a tough old boot, and she may look like one of the witches in Macbeth who’s been overdoing it on the poisoned entrails, but I like her. And Brett’s a good lad. Why bring more scandal down on them when it won’t serve any purpose? There’s no culprit alive to be brought to book.’

  I was surprised to find myself in full agreement with him. ‘And there’s the girl,’ I said.

  ‘Yes. Of course, she may know about his trick with the model aeroplane fuel. I had a word with Ralph Enterkin as soon as you left Briesland House. He’s of the same mind. He’s going to make sure that she holds her wheesht about that.’

  So far, I thought, so good. ‘But you’ll fall on your face if the court wants you to demonstrate,’ I told him.

  ‘It won’t happen. Courts in this country go by what expert witnesses tell them, not by seeing for themselves. I think it’s because of a slavish devotion to the written record.’