The post of Dublin city medical examiner was part-time and proportionately paid, obliging Lafeyre to juggle the workload with his private practice. He had served six years in Africa with the Natal Mounted Police, and he retained the investigator’s instincts developed there. That, together with his qualifications in medical jurisprudence from Edinburgh, made him an invaluable resource in any criminal inquiry.

The city had, nonetheless, invested money in building and fitting out a state-of-the-art morgue on Marlborough Street, just off Sackville Street, and Lafeyre had been invited to choose his preferred equipment and fixtures for its operation. He had sought specifications from modern morgues in England and Scotland, and these had been faithfully honoured. In addition, he was provided with a small office and storeroom in the Lower Yard of the Castle, close to the Army Pay Office.

He had finished his examination and was washing up when Swallow and Shanahan reached the hospital’s small morgue. His driver and general assistant, Scollan, was gathering his surgical instruments. A uniformed constable stood by the door.

‘I haven’t a lot for you,’ Lafeyre shrugged apologetically. He led the way to the examination table and drew back the covering sheet to show Swallow and Shanahan the small body. He nodded towards the uniformed officer. ‘The child’s mother was here to identify the remains. The constable took her statement.’ The constable stepped forward to hand a foolscap document to Shanahan. The G-man initialled it and placed it in his file.

‘She just didn’t have the strength to survive the assault,’ Lafeyre said, glancing through his notes. ‘Well enough nourished, but a slight girl. No signs of sexual activity or venereal disease. She took a terrible beating around the head and face. An extensive fracture on the left side of the skull. Cause of death was massive clotting on the left cerebral hemisphere. The corpus callosum was almost severed at one point. I’d guess there were at least three heavy blows from a club or something such.’

Lafeyre did not need to translate the Latin term for the fibrous material that links the two sides of the brain. If the corpus callosum was destroyed, the amount of force must have been considerable. Although Swallow had drunk his way through two years of medical school, he sometimes surprised Lafeyre with the amount of knowledge he had picked up. ‘You must have been sober in at least one or two anatomy lectures,’ he had once ribbed Swallow. ‘Yeah, one or two,’ Swallow answered, not untruthfully.

‘Could that club be a wooden fence post?’ he asked.

‘Very possibly. Certainly a blunt weapon, swung hard, applied with very great force, repeatedly. This was no quick blow struck in anger; the intent was deadly.’

‘Any other marks or wounds?’