Inspector Wood frowned. ‘You’ll find it difficult to get round those symptoms, Sergeant. The manager was there as a witness. I questioned him closely before I interviewed Dr. Prothero. He described it all in a layman’s terms, of course, but his statement bears out everything you heard the doctor say. It’s a singular thing to have happened, as you imply, but I think we have to reconcile ourselves to the fact that the boy died from natural causes.’
As if not one word of the inspector’s had percolated into his thoughts, Cribb asked, ‘What happened to the plates they ate from?’
‘Fortunately they hadn’t been washed when I arrived,’ said the inspector. ‘I had them put aside with the sherry glasses and the coffee cups as a matter of routine. One never knows, in cases of sudden death.’
‘Good,’ said Cribb, the gleam at last returning to his eye.
‘I’d like everything analysed by the best man available. As a matter of routine, sir,’ he added. ‘One never knows.’
Over a pint of half and half that evening, when all the arrangements had been made and every possible scrap of evidence removed to be examined by experts, Thackeray was sufficiently encouraged by Cribb’s more buoyant mood to observe, ‘You’ve worked out how Prothero could have arranged it, haven’t you, Sarge? It’s something the boy was given to eat or drink, something that could bring on an attack like that.’
Cribb gazed contemplatively into the beer-glass. ‘Just an idea, Thackeray. A memory of something I read. D’you remember the Wimbledon poisoning case last spring?’
‘That doctor?’
‘Yes. Lamson. Hanged at Wandsworth Prison for murdering his young brother-in-law. It interested me at the time because of the poison he employed-none of your conventional arsenic or strychnine. No, it was a doctor’s choice of poison, so rarely used that the lawyers could find only one other case to quote during the trial, and again the poisoner was a doctor. Aconitine, Thackeray. People grow it in their gardens and call it wolf’s-bane. The leaf is not unlike parsley, and the roots, if I remember correct, bear a close resemblance to horse-radish.’
‘Horse-radish! Blimey, Sarge! Horse-radish sauce!’
‘But let’s not leap to conclusions, Constable. Lamson’s victim took nearly four hours to die. Guy was dead within an hour of eating his lunch.’
‘A strong dose, Sarge?’
‘I don’t know,’ said Cribb. ‘We’ll need to find out more about it from the experts. The symptoms, so far as I recall, begin a few minutes after the poison is taken-a numbing of the mouth and throat, obstructing the victim’s breathing. Stomach pains, vomiting and convulsions. Breathing becomes progressively feebler, and eventually death is due to asphyxia or shock. Close enough to Guy’s symptoms to make it worth investigating, anyway.’
‘Worth investigating, Sarge? I should think you’ve got it! He finally decided that he couldn’t save his son from the gallows, so he saved his own reputation instead by slipping him the aconitine, knowing everyone would think it was asthma the boy had died of. It’s a good thing you was there today or there wouldn’t have been no post mortem at all!’
Cribb accepted this heart-felt tribute with a small shrug and added deprecatingly, ‘The pity of it is that there’s no chemical test for identifying aconitine in the human body. It’s about the most difficult of all poisons to base a prosecution on. There are just two ways of identifying it: by taste and by administering it to animals. It’s going to take more than a few dead mice to build a case against Prothero.’
‘Could we find out if he purchased any of the stuff, Sarge?’
‘That wouldn’t help overmuch. A doctor might be expected to have some. It’s recommended as an ointment for use in rheumatism and neuralgia.’
‘Good Lord!’ said Thackeray, his hand going rapidly to the small of his back.
‘I’d stick to red flannel, if I were you,’ said Cribb. ‘Well, Constable. It’s time we made our way back to Brighton, unless you fancy one for the road. The sherry of the house has quite a kick, I understand.’
‘Takes your breath away,’ said Thackeray, grinning widely.
But there were no grins at Scotland Yard later in the week when Thackeray found Cribb reading the post mortem report. ‘I can’t understand it,’ the sergeant said at intervals, as his eyes travelled over the several sheets of finely-written hand-writing. At last he swept the report aside. ‘Not a trace, Constable. Not aconitine, nor any other poison known to science. Nothing in the food, the drink or the contents of the stomach. They carried out the most exhaustive tests, injected frogs and mice with extracts, tried the effects of all the substances on the tongue and produced not one positive result. It’s unbelievable.’
‘You said it would be difficult to identify the poison, Sarge.’
‘Yes, but a man was convicted last March on the evidence of less than a twentieth of a grain and our theory was that Guy was given a heavier dose. They were looking for it, Thackeray. Two of the leading pathologists in the land have signed that report.’
‘Well, what did they report as the cause of death, Sarge?’
‘Respiratory failure. The lungs were found to be uncommonly inflated. Constriction of the bronchial muscles, you see. Some retention of fluid in the lungs. Small haemorrhages on the underside of the diaphragm and in the viscera. I’ve read my medical books in the last few days, Constable. There’s nothing there that ain’t consistent with death from asthma.’
‘It looks as though we’re beaten, then.’
‘Beaten?’ said Cribb. ‘We’re on our own, Constable. That’s the situation. We’ve got to think again. Get down the file with all the statements we took at Brighton. We’ll start from the beginning again. We might never get Prothero into court, but I’m damned if I’ll leave this case until I know how he did it.’
CHAPTER 16
Albert Moscrop had been back in London almost a week when Sergeant Cribb and Constable Thackeray called at the shop. For a moment he failed to recognise them; in his mind they were so firmly connected with his recent short vacation in Brighton that it was as preposterous as if the bathing-machine woman or the bicycle-boy had appeared in Oxford Street. Quite understandably he looked up from a lens he was polishing and simply saw two gentlemen customers. In his professional way he was deciding from their manner and appearance which counter was most appropriate to greet them from, the sporting or the astronomical, when Cribb’s brisk salutation jolted him into realisation.
‘Ah, Mr. Moscrop. Good to see you.’
He nodded vigorously. ‘You too, Sergeant. And the constable, of course.’
‘Smart shop,’ said Cribb. ‘Carpeted, too.’
‘Thank you. Did you-er-’
‘-wish to see you in private? If you please,’ said Cribb.
They passed through a baize door into the rear of the shop. Instruments of every description were ranged about the small room. They had to move a large brass telescope before there was room to sit down on three stools.
‘A most unexpected pleasure, Sergeant.’
‘What was that?’ said Cribb. ‘Oh, our visit. Strictly business, Mr. Moscrop, strictly business. Possibly you heard of the-er-decease of young Guy Prothero.’
‘At Horsham. Yes, I had got to hear of it. What a beastly tragedy for the family! An attack of asthma was responsible, I understand.’