'It's easy enough to test it,' William Haddock said. 'See if it cuts glass.'
Together they crossed over to the frosted-glass window of the operating-room. The sister held the stone between finger and thumb and pressed the sharp pointed end against the glass and drew it downward. There was a fierce scraping crunch as the point bit into the glass and left a deep line two inches long.
'Jesus Christ!' William Haddock said. 'It is a diamond!'
'If it is, it belongs to the patient,' the sister said firmly.
'Maybe it does,' William Haddock said, 'but he was mighty glad to get rid of it. Hold on a moment. Where are his notes?' He hurried over to the side table and picked up a folder which said on it JOHN DIGGS. He opened the folder. In it there was an X-ray of the patient's intestine accompanied by the radiologist's report. John Diggs, the report said. Age 17. Address 123 Mayfield Road, Oxford. There is clearly a large obstruction of some sort in the upper small intestine. The patient has no recollection of swallowing anything unusual, but says that he ate some fried chicken on Sunday evening. The object clearly has a sharp point that has pierced the mucosa of the intestine, and it could be a piece of bone ...
'How could he swallow a thing like that without knowing it?' William Haddock said.
'It doesn't make sense,' the sister said.
'There's no question it's a diamond after the way it cut the glass,' William Haddock said. 'Do you agree?'
'Absolutely,' the sister said.
'And a bloody big one at that,' Haddock said. 'The question is, how good a diamond is it? How much is it worth?'
'We'd better send it to the lab right away,' the sister said.
'To hell with the lab,' Haddock said. 'Let's have a bit of fun and do it ourselves.'
'How?'
'We'll take it to Gold's, the jeweller's in The High. They'll know. The damn thing must be worth a fortune. We're not going to steal it, but we're damn well going to find out about it. Are you game?'
'Do you know anyone at Gold's?' the sister said.
'No, but that doesn't matter. Do you have a car?'
'My Mini's in the car park.'
'Right. Get changed. I'll meet you out there. It's about your lunch time anyway. I'll take the stone.'
Twenty minutes later, at a quarter to one, the little Mini pulled up outside the jewellery shop of H. F. Gold and parked on the double-yellow lines. 'Who cares,' William Haddock said. 'We won't be long.' He and the sister went into the shop.
There were two customers inside, a young man and a girl. They were examining a tray of rings and were being served by the woman assistant. As soon as they came in, the assistant pressed a bell under the counter and Harry Gold emerged through the door at the back. 'Yes,' he said to William Haddock and the sister. 'Can I help you?'
'Would you mind telling us what this is worth?' William Haddock said, placing the stone on a piece of green cloth that lay on the counter.
Harry Gold stopped dead. He stared at the stone. Then he looked up at the young man and woman who stood before him. He was thinking very fast. Steady now, he told himself. Don't do anything silly. Act natural.
'Well, well,' he said as casually as he could. 'That looks to me like a very fine diamond, a very fine diamond indeed. Would you mind waiting a moment while I weigh it and examine it carefully in my office? Then perhaps I'll be able to give you an accurate valuation. Do sit down, both of you.'
Harry Gold scuttled back into his office with the diamond in his hand. Immediately, he took it to the electronic scale and weighed it. Fifteen point two seven carats. That was exactly the weight of Mr Robert Sandy's stone! He had been certain it was the same one the moment he saw it. Who could mistake a diamond like that? And now the weight had proved it. His instinct was to call the police right away, but he was a cautious man who did not like making mistakes. Perhaps the doctor had already sold his diamond. Perhaps he had given it to his children. Who knows?
Quickly he picked up the Oxford telephone book. The Radcliffe Infirmary was Oxford 249891. He dialled it. He asked for Mr Robert Sandy. He got Robert's secretary. He told her it was most urgent that he speak to Mr Sandy this instant. The secretary said, 'Hold on, please.' She called the Operating Theatre. Mr Sandy had gone home half an hour ago, they told her. She took up the outside phone and relayed this information to Mr Gold.
'What's his home number?' Mr Gold asked her.
'Is this to do with a patient?'
'No!' cried Harry Gold. 'It's to do with a robbery! For heaven's sake, woman, give me that number quickly!'
'Who is speaking, please?'
'Harry Gold! I'm the jeweller in The High! Don't waste time, I beg you!'