‘Will, bring the lamp over here if you please. Hold it up so that I may see.’ Raven retrieved the lamp from a table in the corner of the room and held it above Simpson’s head. The doctor pulled gently on the pinna of the child’s ear and moved his own head from side to side as if trying to get a better view of something.

‘Ha!’ he said at last.

He rummaged in his bag for a small metal probe. (Raven always marvelled at the selection of instruments that could be mined from the doctor’s bag.) He then prodded carefully within the ear canal, and after a few minutes extracted a round object which had been lodged within it.

Simpson placed the object upon Raven’s outstretched hand to allow him to examine his find. Raven rolled it back and forth over his palm. It was a spherical concretion which could have been, in its original form, animal, mineral or vegetable.

‘Is it a bead?’ Raven asked, making what he thought to be an intelligent guess.

Simpson punctured the surface of the object with his probe and held it closer to the light.

‘I think it is, or was, a pea,’ the doctor said. ‘Children have a great propensity for placing small items within the cavities of the nose and the ear. This curious behaviour defies any rational explanation, but the presence of such a foreign body does provide us with the reason for the child’s recurrent ear problems. Mystery solved.’

Chuckling to himself, Dr Simpson then unclipped the lid of the leech jar and applied several of the creatures to the most inflamed parts of the ear.

Evidently, he had noted Raven’s previous response.

‘I am entirely sceptical about the efficacy of relentless purging, blistering and bloodletting,’ he said. ‘However, leeches do serve a useful function, if one altogether more limited and specific than our predecessors – and sadly still some of our peers – believe. They are most efficient at reducing engorgement, and they seem to purify the blood in some way, as if removing the poisons responsible for fever.’

When both his work and that of the leeches was done, he stood and indicated that they should all now leave the child in peace. Outside the bedroom door, he whispered something to the mother, handed her a prescription and then began making his way down the corridor.

Simpson halted suddenly and sniffed. Raven was momentarily confused by this until the aroma which had stopped the doctor in his tracks met his own nose, now happily defrosted.

‘I smell toffee,’ said Simpson.

The mother looked alarmed for a moment, as though the making of such confectionery would be frowned upon when there was a sick child in the house.

‘It’s for Christmas,’ she said by way of explanation. ‘I like to plan ahead.’

‘Just so,’ said Dr Simpson, smiling approvingly. ‘I love toffee. Toffee’s very wholesome.’